[[http://www.fanfiction.net/s/8677337/1/Guilty-Sparks Guilty Sparks]] is a ''Franchise/{{Halo}}''/''Franchise/MassEffect'' crossover, the sequel to Fanfic/WhenThereWasATomorrow and the second (and current) installment in ''The Wormhole Chronicles.''

After the PyrrhicVictory at [[VideoGame/HaloReach Reach]], Commander Wade Shepard and the ''Normandy'' Crew escape with their ship in the belly of ''The Pillar Of Autumn'', where they discover their adventures are far from finished. Within weeks of their escape from Reach, they discover [[VideoGame/HaloCombatEvolved a certain ringworld]] upon leaving slipspace, and are forced to explore it when the Covenant overrun The Pillar of Autumn.

Meanwhile, Dr. Liara T'Soni finds herself in for a rude awakening when a Covenant Special Operations team attacks her ship, and after connecting them to Shepard's disappearance, goes on an adventure of her own.

The story concluded on January 28, 2015, with the author announcing his plans to write [[Literature/HaloFirstStrike the next book]] in due time.

[[WMG: This Fanfic contains the following tropes]]

* AllThereInTheManual: Played with- the author posts extensive notes in his blog about the reasons that he put the things he did into the chapter, such as expanding on details of Heritage Fields, how North Korea inspired the Hegemony, why certain characters died and others lived, and thoughts on why the Flood are so terrifying.
* AdaptationalBadass: Staff Sergeant Marvin Mobuto. In the author's notes, he points out that the character got pretty far into The Library (which is crawling with Flood), without regenerating shields or heavy MJOLNIR armor. Even Chief admits that he was a hell of a soldier. Note that this was ''in canon''. Now, in this fic, the author had Mobuto get ''almost'' to the end of the level, making him ''even more badass.''
* AffablyEvil: Zek is kind of boorish but seems to be developing a VitriolicBestBuds relationship with Varvok.
** WordOfGod has said in simple terms that Emperor Narvkel, at least publically, is pretty much an EvilCounterpart to RonaldReagan. His public persona is supportive and grandfatherly, even though he runs a dictatorship worthy of [[NineteenEightyFour Big Brother]].
* AnythingThatMoves: Nelanax has expressed interest in both Liara and Wrex. She likewise trolls Vik with the possibility of sex shortly before a raid on a Batarian bioweapons facility.
* ArsonMurderAndAdmiration: Zek, a high-ranking Kig-Yar sniper, when caught on the receiving end of an {{Invoked}} MeleeATrois, when some of the Normandy crew angered the local wildlife and send them to break the Covenant ranks, had this to say:
--> ''"Oh, this is cheap, underhanded, and sneaky."'' He complained as he watched the scene with a grimace. Then he suddenly smile. ''"Kinda wish I had thought of it."''
* AuthorAppeal: The author has stated in his notes that he's always like the idea of firefights and action scenes going on at an Amusement Park, and thus wrote in the infiltration of Heritage Fields.
* BackToBackBadasses: After [[Fanfic/WhenThereWasATomorrow one]] DoorStopper of a fic and three lengthy opening chapters of another, Commander Shepard and Master Chief, two of the biggest badasses in Science Fiction video gaming, finally team up to kick much ass.
* {{Badass}}: Every named character gets their own moment at one point or another. Special props go to Marvin Mobuto for getting even farther than in canon, Zek's pirates for increasing the number of survivors drastically, Joker for using the Thanix Cannon against the Flood...
* BelligerentSexualTension: Nelanax [[InvokedTrope invokes]] this by flirting with Vik after a particularly heated argument, but she only wants to screw with him. However, this may be developing for real.
* BerserkButton: Don't break [[FriendlySniper Zek's]] rifle when he's shooting with it.
--> "That was my favorite gun!" *cue [[DualWielding twin plasma pistols]]*
** On a more serious note, don't go [[AFatherToHisMen using his men and sending them to their deaths behind his back]].
* BigBrotherIsWatching: The FanNickname [[RecycledInSpace North Korea in Space]] is taken to its logical conclusion on Khar'Shan (with a hint of Antebellum South in it as well, due to their stance on slavery).
* {{Big Damn Heroes}}: Major Silva unleashed a rocket barrage that wiped out a large amount of the Covenant forces guarding the Pillar of Autumn. Actually lampshaded by [[ActorAllusion Buck]].
* BreakTheCutie: [[spoiler: Tali's MindRape]].
* TheCameo: [[Literature/HaloTheFlood Zuka 'Zamamee]] interrupts a Shipmaster meeting to warn his higher-ups that all their focus on "The False Shepherd" is making them ignore the arguably more dangerous Master Chief. He's also mentioned at various points throughout during his scenes where he attacks the Chief, albeit always off-screen. [[spoiler:True to the novelization, he even appears with his Shade turret during the ''Autumn's'' final countdown, and gets an [[AdaptationalExpansion extended fight scene]].]]
* {{Cassandra Truth}}: Zuka 'Zamamee's insistence that the Master Chief is just as big as a threat as Shepard, if not an even bigger one, is ignored by Thel and the other shipmasters.
* CombatTentacles: The Plague Spreader, having several worms stretched into tentacles, has Dragon's Teeth at the tips, which it uses to [[ImpaledWithExtremePrejudice impale]] and convert victims into husks.
* ConspiracyTheorist: Vik'Sajee, a.k.a. "[=3DomLives!=]" lives and breathes this trope. He even spouts counterparts to modern conspiracy theories in his introductory coutscene, such as malicious flouridation of water and space-Bigfoot on Noveria.
* CoolSword: Saya Empa's "Shiakala." An advanced version of a traditional Salarian blade that can both electrocute its opponents as well as spread explosive gel through its cuts to breach walls, though the latter feature first sees use after [[YourHeadASplode slitting a Krogan's throat]].
* CoolVsAwesome: The Flood vs. Reaper Husks.
* CrouchingMoronHiddenBadass: Vik'Sajee is a paranoid, deranged ConspiracyTheorist. However, when Sangheili assassins attempt to murder him, he responds by deploying combat drones and his holdout shotgun, and then flees though a well-devised escape system. [[{{Subverted}} But then curls up in a little ball once he reaches relative safety, because he's still a scared little quarian]].
** He also hacked a [=CDEM=] satalite without being detected, which is like hacking a C.I.A. satelite in terms of skill.
** Let's also not forget the ''improvised [[ThrowDownTheBomblet explosive]]'' he makes in the middle of a firefight with the Covenant.
* TheCuckoolanderWasRight: One of Vik's theories, that Balak's "terrorist" group is actually Batarian Special forces masquerading as terrorists was spot on, and he's nearly killed to cover that up. In addition, his speech about how there is a group controlling the very fabric of society and weeding out cultures sounds ''eerily similiar'' to the words that were used by Sovereign regarding the Cycle. He also claims that the STG is secretly uplifting species like they did with the Krogan. [[spoiler: If you played the third Mass Effect game, you know that this is absolutely correct.]]
* DefiantToTheEnd: Lat 'Ravamee, Shipmaster of the ''Truth and Reconciliation,'' only gets angrier the further the humans get into his ship and desecrate it with his crew's blood. Even when he's alone on the bridge, he charges headlong at Master Chief with his Energy Sword and tries to keep attacking him even when the Spartan has shoved an assault rifle into his mouth.
* DemotedToExtra: Zuka 'Zamamee and Yayap have only ever appeared sporadically throughout the story, as opposed to being the [[VillainProtagonist villain protagonists]] they were treated as in the novelization. WordOfGod says that the changes caused by Mass Effect elements in the story [[InSpiteOfANail would not have changed their sub-plot significantly]] and with LoadsAndLoadsOfCharacters to focus on (and Varvok and Zek playing [[SuspiciouslySimilarSubstitute similar roles to boot]]), let them fall to the wayside. Their sub-plot from the book is still happening, just [[VillainOfAnotherStory off page]].
** This is lampshaded in his final appearance, in which [[spoiler: Zek ''thinks'' he recognizes him, but never names him. Miranda notices he seems especially determined to kill The Chief, but nothing is never made of it and he dies a fairly anonymous death]].
* DidntThinkThisThrough: Thel assigns Zek to supervise Varvok's activities on Halo. What's wrong with this? Well, [[spoiler: Zek is a Kig Yar pirate with an established reputation for subverting Covenant authority, and is instrumental in Varvok's eventual HeelFaceTurn by helping Varvok to spy on the excavation sites, the one place above all others that the Covenant doesn't want anybody to look at. ]] On top of that, Zek is a privateer, and not technically part of the Covenant leadership or command structure. Giving him authority to supervise Varvok not only makes no sense, it is thoughtlessly counter-productive.
* DoubleStandard: Thel is disgusted by Varvok's slaver credentials, yet does not consider the subjugation of the entire Unggoy race by the Covenant to be comparable to Hegemony practices. Varvok himself calls Thel out on this.
* TheDragon: Lieutenant Commander Varvok commands a sizable expeditionary force of Batarian terrorists-turned-mercenaries from the same organization Balak runs. He could also be considered CoDragons with Thel 'Vadamee, as both are directly accountable to The Prophet of Empathy, who himself answers to [[TheManBehindTheMan The Inquisitor]] who in turn is accountable to [[BiggerBad Harbinger]].
* DragonAscendant: Trox takes over Kreave's Chapter of the Blood Pack by default, due to the latter's death in the previous story.
* DumbMuscle: If Wrex is to be believed, this is what Wreav is, which is why Wrex isn't worried about Wreav succeeding in taking control of Clan Urdnot.
--> "He couldn't lead pyjaks to a food cache if you stuck a piece of meat on a string."
* DysfunctionJunction: Liara’s crew on the Lucen is this. Nelanax is a psychotic nymphomaniac who thinks she’s an action hero, Saya Empa is a racist antisocial loner, Vik’Sajee is a paranoid conspiracy nut who thinks the world’s out to get him, and Kayap is a brutalized former slave and a coward… meaning he’s probably the sanest of the bunch outside of Liara and Wrex.
* [[spoiler: EnemyMine: Zek and Varvok decide the best course of action to get off of Halo and away from the Flood and the Covenant was to team up with the surviving humans to hijack a non-infested ship. Varvok and his batarians are not particularly [[TeethClenchedTeamwork fond of this plan due to their racism against humanity]].]]
* [[spoiler: EverybodyLives]]: In sharp contrast to [[VideoGame/HaloCombatEvolved the source material's]] [[EverybodysDeadDave ending]], [[spoiler: Every named character still alive in time for the finale, save Major Silva, manages to escape Halo, along with presumably several hundred Marines, Kig-Yar and Batarians who would have otherwise suffered some very RedShirt deaths]].
* ExactlyWhatIAimedAt: When fleeing from Sangheli on Omega, Vik notes that it was lucky that they missed when shooting at him in a bar... until Liara points out that the Sangheli ''didn't'' miss- they were aiming at the humans.
* FantasticRacism: Considerably less present than in Fanfic/WhenThereWasATomorrow, as the Normandy crew has proved themselves in the eyes of most of the people on the ''Autumn.'' Someone even put up posters across the ship with the alien crew's mugshots saying "Don't shoot these." Major Silva, however, still clearly doesn't care for them.
** Played ruthlessly straight with the Covenant. The enslaved Unggoy are held with the utmost contempt, used as cannon fodder, inhumanely experimented upon, and no one but Liara's crew seems to care about their plight. And then there's the Covenant's genocidal campaign against Humanity to consider as well.
* FriendlySniper: A rare villainous example with Zek, who despite occasionally getting snippy with Vorvak, otherwise treats him with more respect than their Covenant contractors.
** Garrus and Jun also count.
* GloryHound: As with ''Halo: The Flood'', Major Silva is this, intending to bring the Flood directly back to Earth. And when Colonel Holland goes with Chief and Shepard's plan that would ensure that no Flood would be able escape the ring, [[spoiler: Silva declares that Holland is a traitor unfit to lead and mutinies.]]
* HeroicMime: Salarian STG operative Saya Empa doesn't say a word, on account of a damaged larynx.
* HoistByHisOwnPetard: The second Plague Spreader encountered gets this by [[spoiler:''huskifying Flood combat forms''. The process made them stronger, yet since there was no mind to subvert and control like in other organisms, they were not loyal to the Reaper creation. As a result, the Plague Spreader was literally torn apart by the Flood it tried to convert.]]
* IncendiaryExponent: Spitfires, Grunt husks that attack by projectile vomiting liquid metal.
* IronicName: The Prophet of Empathy cares little for his men, and Varvok's men even less so.
** Prophets in Halo Canon tend to be ironic. For example, the Prophet of Truth is covering up the real reason for the war, the Prophet of Mercy usually shows none, and the Prophet of Regret is very impatient and doesn't consider his mistakes at all.
* JerkassHasAPoint: Varvok and Thel ''do not get along.'' At all. However, Varvok does understand human psychology ''far'' better than the Sangheili, which even Thel admits.
* JurisdictionFriction: In addition to more personal reasons, this is why Wrex is not pleased to see [[spoiler: Major Kirrahe]] on Tuchanka.
* LoadsAndLoadsOfCharacters: Two universes worth!
* LowerDeckEpisode: In addition to following [[RecycledInSpace The Normandy Crew mucking around on Halo]], the story also focuses on Liara investigating Covenant activity in the ''Franchise/MassEffect'' universe.
* MauveShirt: Ben, a rookie Shadow Operative and the only one to [[NominalImportance be named]]. [[spoiler: What, did you expect him to survive being cornered by two Hunters? [[ThereIsNoKillLikeOverkill Not a chance]].]]
** [[spoiler: Sergeant Taylor, one of the surviving marines of the previous story, is killed off by the Flood shortly after encountering them. Taylor's squad, Samara and Grunt took his body with them to prevent Taylor from being infected.]]
* MindRape: [[spoiler: Tali's horrific hallucinations of her dead father, Prazza and Kal Reegar are caused by Flood microbes attempting to break her willpower after her suit is ruptured.]]
* [[spoiler: MyMasterRightOrWrong: Nearly all of the ODSTs (except Buck, Romeo and Dutch) follow Major Silva after he mutinies, and go with his orders to shoot anyone who tries to escape the ''Truth and Reconciliation'' to side with Holland.]]
* MythologyGag: Upon learning the Master Chief's real name is John, Commander Wade Shepard muses on the fact that his parents were considering naming John as well. Naturally, "John" is Male Shepard's default name in the character creation screen.
* MySpeciesDothProtestTooMuch: Applies to Drothan, a batarian in the worker caste (located just above the slaves), and you can easily tell how much he's sick with all the crap the Batarian Hegemony does: from the emperor that General Rage said was an asshole that only cares about himself to the terrible quality cartoons that serve to brainwash batarian children.
* NamesTheSame: Finally lampshaded when Sergeant Taylor, who was introduced in the previous story happens to be within earshot of Jacob Taylor when another character tries to get the latter's attention.
* NoSell: Flood Combat Forms do this to Mass Effect weaponry due to the fact that the tiny, high-velocity rounds they fire are useless because they lack the larger surface area of large-caliber projectiles that UNSC weapons fire. Instead, the sand grain-sized rounds go right through with minimal damage to the heavily-decayed and decentralized-vital-system bodies. Team Shepard's [[KillItWithFire incendiary ammunition]] and [[ShotgunsAreJustBetter shotguns]] have more of an effect, though; the former can burn the Infection Forms nestled inside Combat Forms' chests, while the fundamentally-different damage method of the latter tears Combat Forms apart rather than penetrating through them. In addition, most Biotic attacks do little to Combat Forms besides briefly slowing them down, but the Warp attack, at least, can do respectable damage.
* OhCrap: Varvok and Zek are ''terrified'' when they find out that blowing off the heads of Flood combat forms does nothing to stop them.
* OOCIsSeriousBusiness: Not only does Legion refer to itself as an individual yet again, it also [[spoiler:angrily demanded for Tali not to attempt to fix the glitch its been experiencing.]]
* OminousForeshadowing: Just prior to events on the Truth and Reconciliation, Varvok begins hearing reports from his unnerved sergeant about Covenant excavation teams going missing and inexplicable communications blackouts.
* PowerHigh: Nel on "juice", an adrenaline boosting drug that she uses to perform her action hero stunts. Nel has a whole box of the stuff and as [[WordofGod General Rage]] said, her use of it is definitely going to come back to bite her.
* PropagandaMachine: Heritage Fields is an amusement park outside Khar'Shan's capital designed to indocrinate Batarian youth towards fanatical support of their emperor, clearly serving as an {{Expy}} of both [[Videogame/BioShock2 Ryan Amusements]] and [[Videogame/BioshockInfinite Soldier's Field]].
* RedemptionEqualsDeath: After starting the takeoff sequence [[spoiler: Major Silva is attacked]] when The Flood come out of hiding to kill the humans on board the ''Truth and Reconciliation'' and seize the ship for themselves. He's badly wounded and although the infection form that attacked him failed to burrow into him, the flesh on his injury is visibly mutating. [[MyGodWhatHaveIDone Realizing the magnitude of his screwup]], [[spoiler: Silva]] orders his men to abandon ship while he stays behind to slow the ship's ascension so the survivors can escape before they destroy it.
* RemovingTheHeadOrDestroyingTheBrain: Averted with Flood Combat Forms: Shepard reasons that the Flood are zombies and tries taking them out in one hit with a headshot. He gets really annoyed when it doesn't work due to the decentralization of Combat Forms' vital systems.
--> Shepard: ''"Oh bullshit! That's cheating! At least the Husks play fair!"''
** Varvok himself tried the same thing, thinking that the Flood was merely a virus repressing his men's pain receptors. He and his companion Zek were appropriately horrified when it didn't work.
* RewardedAsATraitorDeserves: In the (probably only first) encounter with a Hunter Husk called a Plague Spreader, two elites throw Grunts and Jackals at it to be converted into husks to attack the humans. When the elites run out of "lessers" to feed the Plague Spreader, [[KarmicDeath it turns them]] [[HoistByHisOwnPetard into Husks too]].
* RomanticRunnerUp: Though Shepard is in a healthy relationship with Tali, Liara still has lingering feelings for Shepard. She regrets not acting on them sooner.
* RoomFullOfCrazy: Vik'Sajee's apartment, with empty medication pills, walls lined with pictures linked together in haphazard ways, and a board that Sajee uses to write the latest conspiracy theory running through his head.
* ScrewTheMoneyIHaveRules: Nelanax Catonis is a Turian mercenary working for the Covenant/Blood Pack/Batarian alliance when Team Liara first encounters her, and she is quick to try killing the gang when she runs into them. However, when she discovers her employers are [[spoiler: using slaves in medical experiments]], she almost immediately does a HeelFaceTurn.
* ScrewThisImOuttaHere: After hearing that a squad of his [[spoiler: kig-yar]] were taken and dumped into a suicidal skirmish without his superiors asking him, [[spoiler: Zek]] breaks away from the Covenant. [[spoiler: Varvok]] follows suit to save the remaining [[spoiler: batarians]] under his command.
* ShockAndAwe: The husks created by the Plague Spreader are electrical in nature, which they use to increase their melee damage.
* ShoutOut: Vik'Sajee's name sounds a lot like [[ComicBook/TheQuestion Vic Sage]].
** Saya Empa is an [[NinjaPirateZombieRobot Alien Ninja]] who does not speak as well as his name is derived from 3 Hindu words, [[GIJoe Snake, Eyes,]] and [[VideoGame/{{Borderlands 2}} Zero]]
** Shepard [[VideoGame/Left4Dead calls "zombie bullshit"]] on [[RemovingTheHeadOrDestroyingTheBrain headshots]] not working against the Flood.
* SilentSnarker: As a HeroicMime, all of Saya Empa's snark is done over text communications. He asks Liara if it's too late to drop his more eccentric crewmates off at an insane asylum.
* SwordAndGun: Saya Empa uses both a high-tech sword and a HandCannon. A favored technique of his is to impale a target and use his other hand to shoot their compatriots before they know what's going on.
* TakingYouWithMe: When a group of Elites are about to be overwhelmed by [[spoiler: huskified armored Flood Combat Forms]], one of them ignites a plasma grenade and jumps onto one of his opponents, killing them both in the process.
* TheBusCameBack: Chapter 29 reveals that not only have [[spoiler:the Collectors returned, but the Reapers are using the Covenant to download Sangheili tactics into their programming to make them more akin to a special ops force instead of frontline combatants.]]
** Chapter 30 reveals [[spoiler: Cerberus was waiting for Liara's team to shut down the relay and try to get the Comm Relay station for themselves. At the end of the assault, The Illusive Man appears via Quantum Entanglement Communication to contact Liara and try to negotiate with her, marking his first proper appearance in the series]].
* TheReasonYouSuckSpeech: A large portion of Chapter 27 is dedicated to Thel, Orna and Empathy showing Varvok just how greatly out of his depth he is when he tries to confront them over how they've used Varvok's men as meat shields against the Flood. Thel cuts Varvok's speech short by strangling him and tossing him to the floor, while giving him one hell of a tongue lashing:

--> Thel Vadam: ''You are no longer the master, slaver.'' I AM!
** It gets worse. Varvok learns that the Covenant [[spoiler: got permission from Balak to use his men for suicide missions in exchange for weapons shipments. Essentially, this means the Batarians Balak supplies to the Covenant, including Varvok himself (who sees Balak as a father figure), are expendable not just to the Covenant, but to Balak too. Varvok is horrified at the reveal and at first can't accept it, even when Thel gives him Balak's written orders confirming it.]]

-->[[spoiler:Varvok: "He {Balak} wouldn't sell my men's lives for guns!"]]
-->[[spoiler:Empathy: "He did. For Commander Balak understands, unlike you, that for any cause to succeed, sacrifices must be made. We could obliterate your pathetic excuse for an empire whenever we wish. We don't because we need you... for now. Balak realises this. And now, ''so do you."'' ]]
* TooDumbToLive: [[spoiler: Major Silva believes that the Flood are just simple animals that can be contained and cured, despite seeing what they can do firsthand. And he plans to show this by bringing live Flood to Earth.]]
* UnderestimatingBadassery: Despite Chief pulling him out of Reach (and Shepard's own missions alongside the members of Noble Team in the previous story), Shepard is a little worried that he'll end up "babysitting" the Spartan. Fortunately, Tali corrects him long before the Chief has to prove him wrong.
* TheVoiceless: Saya Empa, literally. A krogan merc crushing his larynx several years prior, removing his ability to speak. This injury cost Empa his candidacy for the Spectres, so he is still a little sore [[FantasticRacism against all krogan]].
* WhatTheHellHero: Nel, having recently taken three doses of her "juice", nearly set fire to the bunker Liara's crew is in and killed them all and gets one of these from Liara. The crazed turian [[NeverMyFault pretty much ignored Liara and later compared her to the military that kicked her out for not "being able to handle how she got things done"]].
* WheresTheKaboom: Zek [[spoiler:when he, Varvok, Chief and the other Normandy crew who went to the ''Autumn'' get on the Longsword and into space when the self-destruct countdown finally finishes up]].
-->'''Zek''': Huh. I was kinda expecting an [[EarthShatteringKaboom earth shattering ka-]]
* WorthyOpponent: After unceremoniously executing a wounded Sangheili, Wrex gives his victim props for not flinching in the face of death. By the end of Chapter 8, the rest of his men agree that the Covenant are this.
* WrongGenreSavvy: When they first face Combat Forms, Shepard, Varvok, and Zek all try for headshots, thinking they're like zombies (and given what Shepard's faced, he has some experience in that department). When this fails, it understandably freaks them out.
** Well, it freaks out Varvok and Zek. Shepard calls it "Bullshit," and "Cheating."