Six months have passed since the events of Warrior Cats: A Vision of Shadows. SkyClan has settled into the lake, though a terrible leaf-bare causes the Moonpool to be frozen over, and the medicine cats fear that they have lost their connection with StarClan. The series revolves around a young ThunderClan warrior named Bristlefrost, ShadowClan medicine cat apprentice Shadowsight, and SkyClan apprentice Rootpaw. As Bramblestar begins to act strangely after losing a life, the three young cats realize that they must come together to defeat a strange threat that the Clan has never seen before.
As usual, there are six books in the arc.
- Lost Stars (Cherith Baldry)
- The Silent Thaw (Kate Cary)
- Veil of Shadows (Cherith Baldry)
- Darkness Within (Kate Cary)
- The Place of No Stars (Cherith Baldry)
- A Light in the Mist (Kate Cary)
This series provides examples of:
- A Day in the Limelight: In an unusual way. There's one scene in A Light in the Mist that's shot from Firestar's perspective, who was last a POV character in his own super edition.
- Anyone Can Die: There are several characters who are seemingly set up to play larger roles before being killed off, such as Stemleaf and Snowtuft. Also, being one of the protagonists does not protect you from death here.
- Bittersweet Ending: The most bittersweet yet. In the final book, A Light in the Mist, Ashfur is defeated, everyone is at peace, and the connection between StarClan and the living Clans is restored once more. However, many cats have died recently, and Bristlefrost not only gave up her life but the very existence of her spirit in order to finish Ashfur, leaving behind her grieving parents, as well as Shadowsight, who blames himself and has lost his connection to StarClan, and her Love Interest Rootspring, who deeply loved her but never got a chance to tell her that he was going to leave his Clan for her.
- Brainwashed and Crazy: In The Place of No Stars, it is revealed that one of the reasons Ashfur is so powerful is that he can control other spirit cats with his mind and force to obey his every command; even attack their family and friends.
- Call-Back: StarClan cats having the ability to possess a living body, something the impostor maliciously uses on Bramblestar and Firestar uses on Rootspring with permission, was previously shown in Omen of the Stars with Cinderpelt's benign possession of Cinderheart.
- Chase Scene: In The Place of No Stars, Rootspring and Squirrelflight are chased through the Dark Forest by the Ashfur-controlled Stemleaf. Matching the eerie feel of the place and the overall tone of the series, the area is foggy and no matter how fast they run, he's always right behind them.
- Cliffhanger: Every book except the last has one.
- Lost Stars: Rootpaw sees the real Bramblestar's ghost, who runs after him begging for help.
- Silent Thaw: Shadowsight is ambushed and has his throat slit.
- Veil Of Shadows: Squirrelflight announces that she's figured out the impostor's identity.
- Darkness Within: Ashfur drags Squirrelflight through the Moonpool into the Dark Forest.
- The Place of No Stars: Ashfur captures Rootspring and Snowtuft and forces them to fight each other.
- Darker and Edgier: The Broken Code is by far the darkest arc to date. The Big Bad is a tyrant who ushers in a dystopian regime as early as the second book, emotionally and physically abuses those in his power, including grooming two of the protagonists, and spiritually torments and controls the souls of the departed. Tonally, the books are very much supernatural horror, with Demonic Possession, ghosts, and the Dark Forest recurring throughout. Finally, the ending is the most bittersweet yet: the villain is defeated and peace is restored, but one of the protagonists is Deader than Dead, the second one is heartbroken, and the third is emotionally scarred for life.
- Defiant Stone Throw: Rootspring does a verbal version twice, during two different Gatherings. The first time is completely by accident (he was trying to tell Bramblestar's ghost to shut up, not the impostor) but gets him noticed by La Résistance; the second, however, is completely intentional, when he decides that someone has to speak out against the impostor and all the other rebels are too scared to.
- Demonic Possession: After Bramblestar's revival in Lost Stars, it quickly becomes clear that something's not right with him. He himself isn't actually possessed; but a wandering ghost. His body is dead and being puppetted by some unknown impostor. The impostor is later revealed to be Ashfur.
- Dystopia: The impostor gradually turns ThunderClan into one. He begins by tightening the rules and implementing small changes, such as having the leader and deputy eat first, under the claim it's just until they bring back StarClan; then he slowly strips away power from Squirrelflight; then he recruits cats to spy on the rest of the Clan; then he enforces harsher and harsher punishments for breaking the rules. By Veil of Shadows, he's openly re-interpreting the code as he sees fit to punish anyone over the smallest indiscretions, with life at camp consisting of everyone else jumpy, scared, and paranoid.
- Eldritch Location: The Place of No Stars is portrayed as such, instead of just the "dark forest" it was in earlier arcs. Full of mist that never fades and slowly-rising waters that drain one's strength, just being in it amplifies your negative emotions. Living cats can dream their way in by focusing on things like anger and hate, which then get exacerbated by the forest, which makes it harder for them to leave. Further, all emotion felt by those within rebound and warp the plane itself: Rootspring is able to escape some of the dark water by thinking of his love for Bristlefrost, while Ashfur's overwhelming hate, jealousy, and obsession are actually obliterating the Dark Forest itself, and by extension StarClan. It's also implied to destroy memories, as Snowtuft remembers almost nothing about his life.
- Eye Colour Change:
- Bramblestar's eyes are noted to occasionally flash blue while the impostor puppets his body.
- Likewise, Rootspring's eyes are implied to turn green when Firestar possesses him, as Darkstripe recognizes the color and freaks out.
- Fake King: The imposter possesses Bramblestar, the leader of ThunderClan, in order to pretend to be him and take charge of the Clan.
- Foreshadowing:
- Shadowsight has two visions with fire symbolism: his first one is of Bramblestar and Tigerstar having a Battle Amongst the Flames, while the second is of fire spreading out from the lake and consuming the clans. While there's a lot of fire, there's also a lot of ash.
- When Shadowsight catches a glimpse of the impostor's true self, he specifically notes his dark blue eyes. There's only one male cat in the entire series who's been described with such: Ashfur.
- Genre Shift: The Warriors franchise as a whole has pretty much always been fantasy-adventure. The Broken Code is primarily a supernatural horror story with elements of political intrigue.
- Hearing Voices: Of the ??? category in Lost Stars. Shadowpaw hears a voice that he thinks is a StarClan cat, and tries to do what it says because he thinks it has the Clans' best interests at heart - even though its advice sounds sketchy. While it is not revealed at that point who exactly the voice is, he accepts later that it wasn't a StarClan cat and has ill intent, as its advice resulted in Bramblestar losing a life and an impostor taking over his body.
- His Name Is......: At the end of Veil Of Shadows, Squirrelflight is about to reveal who the impostor is... and is then abruptly cut off by the end of the book. The next one reveals it's Ashfur.
- I Am the Noun: The impostor responds to anyone questioning his interpretation of the code with "I am the code".
- Immediate Sequel: Lost Stars ends with Rootpaw running from Bramblestar's ghost, who calls after him, "Wait! You have to help me! Please!" The Silent Thaw starts at the same moment, repeating Bramblestar's line.
- La Résistance: Stemleaf and Spotfur form one in The Silent Thaw in response to the impostor's tyranny in ThunderClan and increased influence in WindClan and RiverClan. All of ShadowClan, a good portion of SkyClan and ThunderClan, and some odd few from WindClan and RiverClan are part of it. Some members like Bristlefrost act as spies; medicine cats and those with positions of power, like Tree and Squirrelflight, attempt to subvert the impostor's influence among the other Clans; and Rootspring and Shadowsight investigate the supernatural half of things such as Bramblestar's ghost and how the impostor has cut off StarClan. The rebels also provide shelter for the exiles and are portrayed as unambiguously heroic, but do have some internal division about how best to deal with the impostor, with one group favoring assassination and the other favoring capture and interrogation. They succeed in deposing him in Veil of Shadows, with the group that wanted capture getting their wish, and disband peacefully.
- Mentor Occupational Hazard: In Veil of Shadows, Bristleforst's former mentor Rosepetal is killed in the climactic battle.
- Pyrrhic Victory: The Clans defeat Ashfur once and for all, but Bristlefrost sacrificed her very spirit to do so, Rootspring is heartbroken because he Never Got to Say Goodbye and will never even be Together in Death with her, Shadowsight lost his connection to StarClan and is emotionally traumatized for life, cats are questioning StarClan's wisdom and judgment, and the warrior code needs to be revised.
- Relative Ridicule: Tree is considered weird by many cats due to his non-Clan name, the fact that he can see and speak to ghosts, and the fact that he doesn't have a normal Clan role but rather holds the role of "mediator", which was created specially for him (and which means he doesn't contribute much during peace times). Kitepaw and Turtlepaw bully Tree's son Rootpaw by mocking Tree, and by comparing Rootpaw to him (which Rootpaw finds embarrassing).
- Saying Too Much: In Lost Stars, Jayfeather accidentally says in front of the other Clans in a fit of anger that Mothwing doesn't believe in StarClan. He also snaps about how trying to break the ice on the Moonpool didn't work... in front of Tigerstar, who hadn't been invited and is shocked that everyone went behind his back.
- Sequel Hook: The ending of the last book involves the Clans discussing but not finalizing revisions for the warrior code, which is clearly meant as a lead-in for the announced eighth arc.
- Sneeze Interruption: In Lost Stars, Bristlefrost and Snaptooth decide to spy on Mousewhisker and Berrynose to find out what was so important that they had to sneak away from the hunting patrol to talk about it in secret. Unfortunately, Snaptooth sneezes, alerting the pair and interrupting the conversation.
- Spanner in the Works: Rootspring's mere existence throws a wrench in the impostor's plans. His ability to see ghosts, specifically Bramblestar's, allows him to alert everyone else to what's really going on, and saves Shadowsight's life—the ghostly Spiresight is able to bring Rootspring to Shadowsight after the latter is almost assassinated by the impostor. Rootspring then gets Shadowsight medical aid and the rebels are able to keep him hidden.
- Spin-Offspring: This arc follows Bristlefrost and Shadowsight, who are kits of the series 4 protagonists Ivypool and Dovewing, as well as Rootspring, the kit of the series 6 protagonist Violetshine.
- The Power of Love: In The Place of No Stars, Bramblestar is able to resist Ashfur's mind-control because of his love for Squirrelflight, and Rootspring manages to escape the Dark Forest's energy-sapping black water by focusing on his love for Bristlefrost
- Title Drop: All who ventured into the Dark Forest for the final battle are given the title "Lights in the Mist" in the final book, which is aptly named A Light in the Mist.
- Trapped on the Astral Plane: At the start of the seventh arc, after Bramblestar loses a life, he is unable to return to his body since an impostor has possessed it, leaving his spirit stuck and running desperately around the territories, visible only to Rootpaw.
- Villain Episode: The prologues of the first and final books are from the impostor's point of view.
- Wham Episode: Chapter 18 of A Light in the Mist, for sure, due to Bristlefrost's Heroic Sacrifice, making it the second (third, counting Flametail) time a protagonist has died in her own arc and the first time one has given up her very existence.
- Your Soul Is Mine!: Darkness Within reveals Ashfur has somehow horribly trapped the ghosts of his victims and bound them to his control. When Rootspring tries to call on them, they're portrayed as being in constant pain and anger, and Spiresight gasps out that they're being "forced" to do something. What that is exactly is unknown as of the fourth book, but at the very least, Ashfur uses them as hostages to try and get Shadowsight to help him escape execution. In The Place of No Stars, it is revealed that Ashfur plans to use the ghosts as a mindless, unwilling army against the Clans.
