On the planet Onyx, Kai is leading new Spartan recruits in training to board Covenant ships. The strategy involves shock troop tactics to reach the bridge and input a data spike that will shut down the ship entirely. The UNSC's major disadvantage against the Covenant has been ship-to-ship, and their hope is to train millions of recruits. Kai and everyone else is under the belief that Master Chief died on Reach, propaganda posters herald his legacy. Perez is one of the recruits and questions their training tactics, as after successful deployment enemy attacks ceased immediately and evac went without incident. Kai questions Ackerson over this, and he says the training is to inspire the recruits and not be 100% accurate.
Parangosky and Ackerson meet together and it's revealed that Halsey and Master Chief have landed on the planet. Kwan and Halsey divert to a cave network similar to the one on Madrigal, Kwan was lead by her vision of the mystics while Halsey reveals that she has long studied these ruins, saying "This is where it all began." As they go deeper Halsey notes that changes have been made and eventually come across a science team lead by Miranda, who has been continuing her mothers work. Meanwhile, Soren and Laera search a complex that may be holding Kessler, which Soren calls "Thermopylae."
Master Chief engages with security and is eventually overwhelmed. He plays nice in order to get in the base, then breaks through their defenses to continue unimpeded. Ackerson directs Kai to bring him in, claiming he must be compromised by Makee and the Covenant. Kai and Chief meet in a locker and Kai insists she has orders. Chief refuses to submit but refuses to fight back, letting Kai beat him up in view of the cameras.
Makee is in a dangerous spot as she has actually lost the power to interface with the Forerunner artifact and needs Cortana's help to find Halo, with reluctance she allows Cortana access to their navigation and she immediately transmits all information to Parangosky on Onyx. This was the plan all along, using Cortana as a Trojan Horse to compromise Covenant networks. This does not go unnoticed by the Arbiter and his crew, but they have gone too far to stop and he begins executing loyalists to the Prophets.
While transmitting to Onyx, Cortana is able to find Chief and tells him he needs to find the Keystone. She begins opening doors for Chief and closing doors for anyone in his way. The keystone is their link to find Halo and as he reaches out the larger artifact in front of Makee glows with power.
Tropes:
- Awesomeness by Analysis: Chief and Soren are able to deduce that the Onyx facility is making more Spartans just by scoping out the place for a few minutes, seemingly recognizing the facilities from their own training.
- Big Bad Ensemble: On the UNSC side, we have Admiral Parangosky and Colonel Ackerson, who are gaming the system for their own ends no matter how many people get screwed over in the process. On the Covenant side, we have Makee and the Arbiter, both of whom seek the Halo to fulfill their mission to wipe out humanity and redeem themselves. All four of them stand in opposition to Master Chief, and he's intent on stopping them.
- Blofeld Ploy: The Priest learns of Cortana's transmission and naturally blames Makee for it, despite her claims of ignorance. When he demands the Arbiter execute her, the Arbiter draws his sword as if to follow through, only to then decapitate one of the Priest's entourage before moving on to the rest.
- Break Them by Talking: Chief refuses to fight Kai, but he does stop her from killing him by criticizing her blind obedience to ONI and the UNSC, all while she's beating him to a bloody pulp.
- Brought Down to Normal: Makee has seemingly lost her ability to use Forerunner artifacts, at least by herself, after the union of the Keystones and her temporary death. She believes that she needs the Chief's help to access the vision of the Halo, which is about to happen at the end of the episode.
- The Bus Came Back: Miranda Keyes returns for the first time since the previous season, having been working with Halsey's research in the catacombs on Onyx.
- Cassandra Truth: Eventually Subverted. Chief does try to explain to Kai what really happened on Reach, but he knows she won't believe him. After she beats him to a pulp and leaves him, her trust in Chief wins out and she believes his story.
- Curb-Stomp Battle:
- Once led into the base on Onyx, the Chief easily takes down the squad of Marines that currently have him in tethers.
- He's on the receiving end of this trope from an armoured Kai, though John doesn't bother to fight her physically, instead using his words as weapons.
- Despair Event Horizon: The beatdown Chief gets from Kai leaves him about ready to give up. Fortunately, Cortana gets him back on his feet when she reveals she's with Makee and the Arbiter.
- Determinator: John hasn't recovered from his injuries and is now up against Kai in full armor, but he simply refuses to go down as long as he's conscious. Kai ultimately has to backhand him unconscious to make him stay down, and simply leaves him there rather than follow through with arresting him, shaken by his words.
- Enemy Civil War: Makee has baited the Arbiter with the chance at finding Halo, and there are factions on board their ship that are still loyal to the Prophets. When it's discovered that Makee let Cortana access their comms, the Sangheili Priest demands her execution, so the Arbiter begins attacking the loyalists to protect his own agenda.
- Everyone Has Standards: Kai has gone along with ONI's lies thanks to Ackerson's manipulations, but she's outright horrified that she's not only been deceived about what happened on Reach, but that her goal is to train the next generation of Spartans as suicide troopers.
- Flawed Prototype: Parangosky and Ackerson believed a major problem with Halsey's Spartans was that they were too expensive and too time-intensive to use in critical missions. Ackerson's Spartans are design with mass production in mind, able to recruit millions at a time and deploy them against critical targets without worrying if they can survive.
- Foreshadowing: Kwan follows images of the mystic to find a nearby well, similar to one she saw on Madrigal. She desperately jumps inside to avoid patrols and she's saved from a hard landing by what appears to be a Hard Light bridge. It's soon learned that there is a Forerunner cave system hidden underneath.
- Internal Reveal: John tells Kai about what really happened on Reach, and though she doesn't want to believe him, her trust in him runs deeper than her loyalty to ONI.
- It's Quiet… Too Quiet: Perez is rightly suspicious when the boarding simulation suddenly goes quiet after the spike is delivered, when (as Kai later points out from experience) their escape from the ship should be twice as difficult as their arrival. Kai thinks Ackerson deliberately rigged the simulation to let them win, but the much darker implication based on Ackerson's speech about belief (and the nature of the SPARTAN-III program in Halo lore) is that the spike is where their mission ends.
- It's Raining Men: The boarding simulation has the SPARTAN-IIIs engage in a space variant, jumping from their transport to the Covenant ship.
- Logical Weakness: Covenant ships are shielded and have precision weaponry, which requires the UNSC to have a three-to-one advantage to counter. But the UNSC does significantly better with infantry, so they have developed a strategy with the new Spartan program training them to deploy en masse in EV suits in order to board the ships and use a data spike to sabotage their computers. Kai makes the analogy that no matter how far a sniper can reach they can't stop a swarm of bees.
- Mythology Gag:
- Onyx from the novel Halo: Ghosts of Onyx was a world initially believed natural but revealed to be a Dyson Sphere made up of Forerunner sentinels. Here it's revealed to have a Forerunner cave network similar to Madrigal, and Halsey implies this was where the UNSC's original knowledge of the Forerunners came from.
- Kai is a previous-generation Spartan training the next generation, something that happened with Kurt for the SPARTAN-IIIs and Jun for the IVs. Their simplified armor heavily resembles the canon design of the SPI armor most IIIs were given.
- The Arbiter is shown burning a small symbol into his chest before putting his armor on. In Halo 2, the Mark of Shame was burned into high-ranking Elites who are criminals or have gravely failed the Prophets and have been selected to become Arbiters. This Arbiter choosing the mark vs. the original Arbiter being branded as a form of torture is a reflection of minor differences in the characters.
- Like in canon, the SPARTAN-III program is using its troopers for suicide missions and names teams after melee weapons (with Javelin emulating a particular nugget
), and Onyx is located by way of a Covenant-tracked Cortana transmission. - The Sangheili Priest's name is given in subtitles as Uto 'Mdama. Jul 'Mdama was the leader of a post-war Covenant remnant faction seen primarily in the Spartan Ops campaign of Halo 4.
- One-Man Army: Once again, John shows just how formidable a SPARTAN-II can be even without armor as he takes out a roomful of black-ops soldiers while his right arm and leg are shackled.
- Point Defenseless: Zig-zagged. The simulated Covenant ship does have point defenses, but armored humans are too small for the targeting scanners to pick them off as easily as they would other threats.
- Properly Paranoid: When Cortana asks for comm access, Makee points out that just because she needs Cortana doesn't mean she trusts her. Cortana shoots back that Makee has no choice but to trust her, so Makee has to grant her request.
- The Reveal:
- The deal Parangosky cut for the Chief's life was with Cortana, who was left behind to be captured intentionally so she could infiltrate the Covenant network and relay data about their fleet.
- Kai didn't betray Silver Team, and was left in the dark about Reach until the attack happened.
- Makee has lost the ability to activate the keystone and has been hiding this from the Arbiter. She believes she can restore that ability if John interacts with it, which is why she was keeping him from being killed.
- Halsey spent years studying a Forerunner cave network on Onyx, one very similar to the one found on Madrigal. She's known about the Forerunners for a long time, and tells Kwan "This is where it all began."
- Sheathe Your Sword: Chief refuses to fight Kai but also refuses to stand down. Kai has her orders and knocks him around, but Chief uses that time to make her question Ackerson's lies. He also knew they were on camera, so Kai couldn't be reprimanded for not doing her job.
- Spotting the Thread: Kai becomes suspicious when Perez and her squad complete the simulation, only for there to be no Covenant ambush after planting the data spike. In her experience, getting onto a Covenant ship is a lot easier than getting off one, which leads her to conduct her own investigation. She soon learns that the mission is supposed to end for the Spartans right there and then—and that they won't be coming back.
- Suicide Mission:
- Cortana was sent on her infiltration mission with the expectation that she would be destroyed sooner or later, but would be able to steal data on the Covenant fleet before that eventuality.
- It's implied that the SPARTAN-III program is intended to throw waves of expendable soldiers at Covenant ships to destroy them from within, since ship-to-ship combat favors the Covenant three-to-one.
- Stealth Pun: Kwan is constantly chasing the apparition of the shaman leader who leads her to the Forerunner tunnel network. In layman's terms, she's chasing a ghost of Onyx.
- Super Prototype: Unlike the game canon SPARTAN-IIIs, Javelin Team is comprised of regular, unaugmented conscripts, and their only connection to Spartans like Chief or Kai is the use of Powered Armor that is nonetheless mass produced and cheaper — like the book canon ones. When Chief gets into the base, it's obvious that Kai would be the only one able to confront him.
- Tap on the Head: Chief uses his natural strength and skill to wreck a dozen UNSC guards before added numbers convince him to be taken in captive. It's evident he uses some restraint but is told that one of them may die from his attack regardless. Given the circumstances he is not especially distraught, laying blame on bad leadership for sending those men after him in the first place.
- Trojan Prisoner:
- John fights the team sent to take him out then allows the second squad to capture him. Once they think they have him restrained in a cell, he escapes again, now inside the base without having to fight past the front gate.
- Cortana was left on Reach to be taken by the Covenant so she could infiltrate their network and relay that data back to Parangosky.
- Unwinnable Training Simulation:
- The Spartan recruits are running drills to infiltrate a Covenant ship, which has random settings every time because they can't predict how the Covenant will respond. Perez complains the first time because their near-victory is ended by a Needler shooting them seemingly out of thin air.
- Something of an inversion happens later, once Perez leads a team to successfully deploy a data spike. The ship not only shuts down, but all the Covenant vanish, allowing for a clear evac. The ease of this is caught by Kai and Perez, the former accusing Ackerson of rigging the game in their favor.
- Voice with an Internet Connection: Cortana manages to gain access to the facilities on Onyx, and finally reunites with Master Chief. She immediately goes to work using the base automation in his favor, opening doors for him while locking others out.
- We Have Reserves: Ackerson makes it clear that the SPARTAN-III program isn't designed to send the best of the best to keep fighting the Covenant and do it until the war is over, but rather to send the best to die and claim victory, no matter how many troops it takes.
- Zerg Rush: SPARTAN-III tactics revolve around swarming Covenant targets so that one can break through and achieve the mission objective. Perez in particular realizes they'll never achieve their objective unless they rush the bridge as a unit, so at least one of them will break through to deliver the spike.
