Being an Ultimate Universe fanfiction of My Little Pony: Friendship Is Magic and G4 as a whole, Spectrum is packed with references, Call Backs and Call Forwards to the series, comics, books and movie.
Those elements of the Expanded Universe that are directly fundamental to the main story are listed on the basis of the work they originated from; otherwise, the remainder are listed chapter-by-chapter.
Beware of unmarked spoilers.
Individual Works
- Twilight Sparkle and the Crystal Heart Spell
- Princess Cadance's backstory from the chapter-book is acknowledged as canon by Spectrum, and gradually expanded upon, until it forms a cornerstone of the plot.
- As early as Chapter Three ("They Are Us"), Cadance is introduced reflecting upon how she has learned to fly. This is an indicator as to the Broad Strokes approach the story takes, since Cadance was born in Spectrum as a seemingly flightless pegasus.
- When Alex enquires from Cadance in Chapter Eleven ("Those On Pilgrimage") how come she is an alicorn, Lyra recounts to Twilight and the Bearers that Cadance told him the story (off-screen) about her meeting with Prismia. In an instance of Arc Welding, Prismia's necklace is confirmed to be the Alicorn Amulet.
- Prismia is mentioned several times during the Battle of Boston; first, in Chapter Sixteen ("An Angel's Wings") when Cadance gives a Badass Boast to Archmage Twilight about how the sorceress Prismia tested her. Then, Chapter Nineteen ("When The Dust Settles") ends on the Wham Line that Cadenza, her counterpart from Imperial Equus, never even met Prismia.
- Cadance telling Alex the tale of her childhood and ascension is shown in full with the Interlude between Acts Two and Three, "Child of Crystal".
- Rainbow Dash and the Daring Do Double Dare
- The book which Rainbow Dash is waiting for to arrive in the mail during Chapter One ("The Human") is Daring Do & The Volcano of Destiny, thus situating the events of this book as around Season 3 and close to the "present-day" chronology of Spectrum.
- The rogue zebra Braze is described as a Prince of Farasi and the younger brother of Prince Abraxas.
- Similarly, the Spirit Circle is stated to be one and the same with Ponehenge.
- The Daring Do Adventure Collection
- The Prologue introduces the Half-Gilded Horseshoe, which also showed up in Rainbow Dash and the Daring Do Double Dare. Here, the Horseshoe is the last heirloom of Tau Sunflare.
- Daring Do's induction into a Magic Council at the end of The Daring Do Adventure Collection is mentioned in a private meeting between Prince Abraxas and Spell Nexus during Chapter Thirteen ("Concordia Maxima").
- The nicknames of "Candid" and "Cunning" for Abraxas and Nexus, respectively, are also lifted from the titles of the six-member Council.
- My Little Pony: The Movie (2017)
- A starting clue that elements from the 2017 movie will factor into Spectrum can be found in Chapter Five ("Understanding Dawns"), when Cadance dream-walks into Blueblood's dreams and finds him sharing a romantic fantasy with Captain Celaeno. Blueblood mentions hooking up with her during a visit to Klugetown.
- The Storm King's name is brought up a couple of times over the course of Act One, with increasing urgency.
- It starts out innocuously enough when Chapter Eight ("The Heart Goes Last") has the Imperial Redheart give Icewind an abbreviated account of the Solar Empire's history, mentioning the Storm King as an enemy.
- Later, in Chapter Eleven ("Witnesses") when Celestia sends out the Concordia's Call throughout Equus, the Kirin Mikado wonders if the feeling of static electricity was caused by him.
- Chapters Twelve ("To Seize The Day") and Thirteen ("Concordia Maxima") ramp up the tension, as Queen Chrysalis herself is aware of the Storm King, the Kirin government prefer striking deals with him, and both the Abyssinian and hippogriff rulers initially treat him as a bigger concern than the crisis on Earth.
- Act Two sheds further light on why the hippogriffs, and other equine nations by extension, agreed to an alliance with the future Imperial Equestria; the Co-Harmony Sphere offered them protection against the Storm King.
- Both Chapter Fifteen ("Two Faces") and Chapter Twenty ("Accept The Dawn") contain instances of a hippogriff character speaking of the good the Solar Empire has done to keep the Storm King at bay.
- One of the flashbacks Princess Luna witnesses in Archmage Twilight's memories during Chapter Seventeen ("Thus, Lift Me Up") has a Changeling Queen, Papillate, offer an Enemy Mine deal to Twilight by providing her with an Obsidian Orb and a warning about the Storm King's growing power. A later flashback in the same chapter, set at the foundation of the Co-Harmony Sphere, confirms the Storm King was driven back.
- Act Three brings this to its a local conclusion;
- Towards the end of "Child of Crystal", the Interlude turns into a Wham Episode by revealing that the Storm King orphaned Cadance, intending to steal her power for his own.
- Following another few mentions, the Storm King finally appears in the flesh as Chapter Twenty-Six ("Here's To You") draws to a close, entering the story as an Arc Villain.
- When Tempest Shadow is introduced in Chapter Twenty-Six ("Here's To You")note , her inner thoughts betray a note of regret about Rambler, the travelling pony whose caravan she joined during her wanderings, which is consistent with her backstory in both the comic-book My Little Pony: The Movie Prequel and the chapter-book The Stormy Road to Canterlot.
- In that same chapter, Galena explains to Celestia and Luna that she met Scorpan three times, and in his possession was the Staff of Sacanas. This is taken from The Art of My Little Pony: The Movie, according to which one of the original plans for the Movie was that Scorpan indeed used to be the owner of the Staff.
- On another note, Galena is introduced as one of the workers on the renovations to cover the Canterlot Palace's throne room in crystal and to add a second throne for Luna on the dais, thus bringing the room closer to its appearance as of the Movie.
- Radiant Hope - My Little Pony: FIENDship Is Magic (Issue #1) & My Little Pony: Friendship Is Magic (IDW) (Issues #34-37)
- Princess Luna's dreamwalk that concludes Chapter Twenty-Four ("Unveiled")note is another instance of Spectrum showing its hand in making changes from the official canon in order to serve its narrative; here, Radiant Hope is explained to be the daughter of Princess Amore.
- And the very next chapter, Chapter Twenty-Three ('Here's To You') takes this up another notch, by heavily implying that Radiant was Cadance's mother.
- Celestia and Luna come to suspect Cadance's parentage by having Celestia sing the lullaby "Cold Hooves, Warm Hearts", a lullaby that originated in the chapter-book Princess Cadance And The Spring Hearts Garden, with slightly different lyrics. Whereas the song from the book is identified as the favourite lullaby of Cadance's daughter, Flurry Heart, Spectrum has Cadance recognise it as a song that her own mother would sing to her...
Chapter-by-Chapter
- Chapter One - "The Human"
- Spectrum situates itself as set after the events of the episode "Magic Duel", since Twilight is busy studying the Alicorn Amulet. However, dialogue from the chapter demonstrates early on that the story is prepared to take liberties for its own purposes, since Trixe is said to be facing a prison sentence for her actions.
- Later chapters clarify that the episode's events occurred a year before the start of the story, but that Trixie was formally sentenced only four weeks beforehand.
- Spectrum situates itself as set after the events of the episode "Magic Duel", since Twilight is busy studying the Alicorn Amulet. However, dialogue from the chapter demonstrates early on that the story is prepared to take liberties for its own purposes, since Trixe is said to be facing a prison sentence for her actions.
- Chapter Two - "Friends On The Other Side"
- Princess Celestia opens the chapter reflecting on a future trade deal with the Kirin, yet these Kirin are presented somewhat differently from those on the show, as a Japanese-style commercial empire.
- Supplementary material on the forum confirms the existence of the Kirin from the Peaks of Peril as a commune who live separately from their homeland's culture and politics.
- On Lyra's living-room wall is a String Theory pegboard that includes a photo of the Observer Pony, himself a Shout-Out to Fringe.
- Princess Celestia opens the chapter reflecting on a future trade deal with the Kirin, yet these Kirin are presented somewhat differently from those on the show, as a Japanese-style commercial empire.
- Chapter Three - "They Are Us"
- Celestia obliquely reflects on her past failure with Sunset Shimmer.
- While discussing the myth of humans and ancient legends in general, Applejack and Rarity bring up the legends of Rockhoof and Mistmane.note
- The connection between Spectrum and a Broad Strokes version of G1 is introduced by Lyra with a book about an expedition to the mythical Dream Valley. Celestia herself explains she once met a mare called Firefly when she was very young.
- Chapter Four - "Nightfall Over Boston"
- Although this chapter is light on content pertaining to the G4 Expanded Universe, the PHL High Command's members includes the one-episode character of Gladmane, alongside popular supporting-cast ponies such as Cheerilee, Vinyl Scratch, Doctor Whooves and Spitfire.
- Chapter Five - "Understanding Dawns"
- It's blink-and-you'll-miss-it, but Princess Luna notes that Prince Blueblood is an heir of the line of Princess Platinum, thus linking him to one of the six Hearthwarmers.
- Chapter Six - "The Trinity Harmonious"
- Bonbon's secret identity as a superspy, introduced as a joke in "Slice of Life" and further explored in the chapter-book Lyra and Bon Bon and the Mares from S.M.I.L.E., is not only proven to be part of Spectrum's continuity, but is essential to the plot for the next two chapters.
- Chapter Seven - "Unto The Breach"
- Galena informs Alex that he carries on him an object of great power that could turn the war's tide; the Rainbow of Light. As it turns out, he's lost it in the Everfree Forest.
- Chapter Eight - "The Heart Goes Last"
- With Celestia and Luna unable to teleport in because of drained mana, they borrow the Medallion of Chancellor Neighsay.
- Chapter Nine - "In Darkest Hour"
- As the PHL rank-and-file are hypothesising at the campfire about what evil force may have corrupted Queen Celestia, Johnny C brings up the names of two villains from G1, Somnambula The Witch and Arabus The Cloud Demon.
- Chapter Ten - "Witnesses"
- Sint Erklass and Ilsa Erklass, OC Reindeer, mention checking in on the Gift Givers of The Grove before heading to Equestria.
- The zebra rule to receive the Call is Prince Abraxas, introduced battling the Grootslang. In the same segment, Zecora's old friend Marini also makes a cameo.
- Chapter Eleven - "Those On Pilgrimage"
- One of the foreign horse delegates from "Magic Duel", popularly known to fans as Amira, makes an appearance at the beginning of the chapter visiting her husband in prison. While Amira returns to the background for the rest of Acts One and Two, her and her family's prominence will rise by Act Three.
- Chapter Twelve - "To Seize The Day"
- Celestia takes Luna and Galena to see the Crystal Mirror stored in Canterlot Palace. While discussing the Mirror's history, there is some debate between the sisters as to which version of the story of how Starswirl banished the Sirens is true; him going at it alone in a musical contest, or with the aid of the Pillars of Equestria.
- The dialogue suggests the truth lies somewhere in between in Spectrum, with Starswirl facing the Sirens together with the Pillars as his band.
- Celestia takes Luna and Galena to see the Crystal Mirror stored in Canterlot Palace. While discussing the Mirror's history, there is some debate between the sisters as to which version of the story of how Starswirl banished the Sirens is true; him going at it alone in a musical contest, or with the aid of the Pillars of Equestria.
- Chapter Thirteen - "Concordia Maxima"
- The entirety of the chapter is set in the Hall of Unity, revolving around an appropriately important international summit.
- While the Tirek referred to by Spykoran, himself a much-much-older version of G1 Spike, is the one from G1, Scorpan is identified as his brother, similar to G4.
- Chapter Sixteen - "An Angel's Wings"
- The brainwashed Imperial Spike's flash of memories indicates that before he and Rarity got captured by the Solar Empire, their journey took them past Hope Hollow.
- Chapter Seventeen - "Thus, Lift Me Up"
- Twilight's memories of the Crystal War make mention of liberating a little mining town outside the Realm, reaffirming that not all ponies up North live within the city's magical dome as seen in "Tempest's Tale".
- Amongst the equine national leaders present at the foundation of the Co-Harmony Sphere are the Duke and Duchess of Maretonia, here named as Nibiru and Silili.
- Chapter Eighteen - "Moonrise Over Boston"
- The Lieutenant of the Imperial Guard outpost at Fellsmere Park is Fire Flare, a one-off background character and stunt performer from "The Summer Sun Setback".
- Chapter Nineteen - "When The Dust Settles"
- The disguise Princess Luna wears is a dead ringer for her Season One appearance, minus wings.
- Luna casually tells Maxine that she used to bear the Element of Laughter.
- Interlude - "Child of Crystal"
- As she reminisces on her past, Prismia recalls drawing Clover the Clever on a long chase that culminated in a garden, implying she is also the sorceress who carried the Memory Stone.
- Chapter Twenty-Three - "Castles In The Air"
- Lady Cadenza's replacement on her seat of the PHL High Command is Olivine Jewel, a crystalpony who was a key character in Princess Cadance And The Spring Hearts Garden.
- When analysing the copy of Alex's runes, Qabil al-Husan identifies some of them as wielded by an ancestor of his during a revolutionary war against Saddle Mareabia by their former colony of Farasi.
- A few comments by Headmaster Spell Nexus indirectly reveal that Starlight Glimmer is his goddaughter, which is followed up on in subsequent chapters.
- Chapter Twenty-Four - "Unveiled"
- Amongst other events from the "official" canon of Friendship is Magic that Princess Luna witnesses during her dream-walk, she sees Twilight as an alicorn, fighting a shadowy trio of villains, and finally, the very last shot of the series.
- Chapter Twenty-Five - "Family"
- A recurring motif throughout this chapter and the next is the presence of two children's books, Under The Sparkling Sea and The Dragons On Dazzle Island, the titles of real-life Friendship is Magic picture-books by Mary Jane Begin, notable for their hand-painted, water-colour artwork. In Spectrum, the books' equivalents turn out to have been written and illustrated by Princess Celestia herself, working under the pen name of Sunny Skies.
- Flash Sentry, the pony, makes a very brief and innocuous cameo during Hadia al-Husan's reception to the Crystal Realm.
- Cadance mind-delving into the memories of the Imperial Spike leads to a revisitation of scenes lifted from "Gauntlet Of Fire", until they take a dark turn thanks to the Imperial Timeline.
- Keeping watch over Imperial Spike in his cavern beneath the Crystal Realm's library is the Crystal Bard.
- As the realisation sinks in that Thorax has run away from the Hive, Pharynx bitterly reflects that this has happened before with Kevin.
- The tea-time scene between the Three Sisters shows Princess Celestia in her little-pony form for the first time. Interestingly, while Celestia's natural mane-colour as a little pony is pink, she prefers dyeing it blonde, consistent with her disguise in "Queen For One Less Day". The comic's story is even mentioned later to have occurred in some form, with Celestia disguising herself to find the Alicorn Amulet after it got stolen by a street urchin, whom she freed from their cruel aunt.
- Chapter Twenty-Six - "Here's To You"note
- During their conversation at the Hall of Unity's archives, Twilight tells Lyra about visiting Monacolt (Princess Celestia And The Summer of Royal Waves), and reminds her to pack a telescope for the Expedition so she can watch Secretariat's Comet pass over the Arctic.
- Before accompanying her friends to see Twilight off from the Hall of Unity, Fluttershy is found seeking consolation for Discord's loss in her Chamber of Extreme Knitting.
- Coming to get Fluttershy, Applejack commiserates with her over losing a loved one yet holding onto the hope they may return someday, referencing her Great-Uncle Chili Pepper. This is a humorous allusion to the much-reviled "The Good, The Bad And The Ponies" arc of the comics, where finding Chili Pepper was the catalyst until he got forgotten halfway through by the narrative.
- Watching from the stands at the departure of the Expedition Into The Unknown, Shining Armor briefly witnesses Headmaster Nexus formally handing over his duties as Archmage to Professor Inkwell. Shining notes this is somehow appropriate for the times, since Inkwell was a hero who helped defend Canterlot from an invasion by Shadows.
- Amongst Lyra's science team on the Expedition are A.B. Ravenhoof, Brumby Cloverpatchnote and Miss Vine, here given the name "Emerald Vine".note
