Triad forces occupy the school in search of the Chalice of Arimathea. They're using an artifact underneath the school to suppress all magic, de-powering witches and keeping vampires contained during the day (as their rings don't work). They're also armed with crossbows and wolfsbane against vampires and werewolves. The soldiers' leader Burr is especially sadistic and delights in hurting the students. Veronica Greasley tries to keep MG safe, but he knocks her out and rescues his friends. Alaric disables the magic-dampening artifact, allowing the students to overpower the Triad soldiers. Alaric then admits to the whole school that he put the artifact in place as a contingency plan, in case he had to deal with the students. He asks the student council to decide whether he should remain the headmaster. Veronica apologizes to MG, claiming that she didn't know that Burr was so sadistic. MG retorts that he doesn't wish to be her family anymore.
Meanwhile, Clarke and Landon go to a Triad warehouse in search of the chalice. Landon finds a chalice, only for Clarke to smash it and reveal that he knew that Landon was lying. He was counting on Landon unconsciously pocketing the real key, which turns out to be an ancient arrowhead. What he didn't tell Landon was that Malivore plans to use Landon as a biological host with which to rampage across the world and start a new species. The Headless Horseman then arrives and takes Landon and the arrowhead. At the puddle, the Horseman tosses the arrowhead into the puddle, only for Hope to catch it telekinetically. She kills the monster. However, Clarke gets his hands on the arrowhead and tosses it into the pit, awakening Malivore. Landon uses the Horseman's bone whip to snap Clarke's neck. He then tells Hope everything Clarke has told him and she realizes that she is the key to destroying Malivore. She snaps Landon's neck to keep him from stopping her. She then calls Alaric and asks him to pick up Landon and to burn all her files, since she plans to toss herself into Malivore, which would erase her from everyone's memory. Then Clarke gets up and tells her his real plan was to find a way to destroy Malivore, whom he still hates for abandoning him. Hope uses a mimic spell to force Clarke to leap into Malivore with her. Landon regenerates and gets up, not sure why he's at the facility, and sees a deep pit instead of Malivore's puddle, implying the creature is indeed dead.
- All Your Base Are Belong to Us: Triad soldiers occupy the school in search of the Chalice of Arimathea.
- Anti-Magic: Veronica sneaks into the school using a secret tunnel and activates an artifact that negates all magic in the school. This applies to witches' powers, the vampires' sun-protection rings, and any wards or spells active at the school.
- Attack Its Weak Point: Landon realizes that the Headless Horseman's weak point is its disembodied head, which is hanging off its belt under the cloak. Hope manages to get the head loose, after which Landon tosses it to her, and she impaled it onto a broken pipe. The Horseman's body drops dead.
- Bittersweet Ending: The school is saved, Malivore and Clarke appear to be destroyed, but Alaric's future as headmaster is up in the air, Hope is gone, and Rafael may be stuck as a wolf forever.
- Call-Back: Just as Burr is about to shoot MG, the twins make bugs come out of Burr's mouth, probably remembering the mummy pulling this trick on them earlier.
- Continuity Nod:
- The totem that is used to stop the students from using magic is revealed to be an artifact created by the Travelers, who were the main antagonists of Season 5 of The Vampire Diaries.
- The twins find an artifact in their fathers office that is clocked with magic which is revealed to be the Ascendant which fans of The Vampire Diaries know was used to lock their Evil Uncle Kai away in his latest prison world at the end of Season 8.
- Curb-Stomp Battle: Once the Anti-Magic artifact is shut down, witches, vampires, and werewolves quickly overpower the Triad soldiers.
- Depleted Phlebotinum Shells: Apparently, the Triad have weaponized Malivore by making bullets out of its mud. The bullets can kill anything supernatural, which also applies to witches, vampires, and werewolves. If it's not immediately fatal, the taint starts spreading from the would and will eventually kill the person.
- Dragon with an Agenda: After Hope realizes that only her blood can destroy Malivore permanently Clarke reveals that he was only trying to release his father because he knew that he would escape eventually. Knowing that their is a permanent way to kill him leaves him delighted and he is all for Hope sacrificing herself.
- "Eureka!" Moment: Hope realizes that Malivore was created by a ritual involving the blood of a witch, a werewolf, and a vampire, it can be ended by the same combination... like her own blood.
- Even Evil Has Standards: The Triad may hate supernatural creatures, but Veronica had no idea that Burr would be so sadistic and would be willing to hurt children.
- Fakin' MacGuffin: It turns out that Landon lied when he said that the chalice was the final key. He brings Clarke a chalice, only for him to smash it against the floor, pointing out that he wouldn't be able to do it to the real key. He knew that Landon was lying but he wanted him in the proximity of the real key, so that he would subconsciously pocket it.
- Family of Choice: MG chooses his "super friends" over his mother and their Secret Legacy.
- Headless Horseman: One shows up a few minutes after Landon finds the arrowhead. It looks typical of the trope, but uses a bone whip as its weapon. During its fight with Hope, it keeps blocking Hope's attempts at casting spells, until Landon figures out that it's disembodied head is its weak point. As soon as Hope stabs the head with a broken pipe, the Horseman's body drops dead.
- Heel–Face Turn: The Gorgon turns Burr to stone, just as he's about to shoot MG.
- Heroic Sacrifice: Hope leaps into Malivore in order to destroy it, figuring that her tribrid blood is the only thing that can do that.
- Instant Sedation: Triad dart guns instantly put people to sleep without any harmful effects. This applies to regular humans as well as vampires.
- Mode Lock: In order to stop Burr from hurting the children on the bus, Rafael uses Hope's ring to turn into a wolf and asks the twins to cast an invisibility spell on him. He quickly deals with the Triad soldiers and Burr, before running off into the woods. However, since Hope is the only one who could turn him back, her being Ret-Gone means he may be permanently stuck as a wolf.
- Neck Snap: First Landon snaps Clarke's neck with the Headless Horseman's bone whip. Then Hope casually snaps Landon's neck after kissing him. Both of them survive it, given that one is a golem and the other is a phoenix.
- Nice Job Breaking It, Hero: Hope leaves the arrowhead on a windowsill while fighting the Headless Horseman. Then she completely forgets about it and starts professing her love for Landon. Clarke shows up and simply takes the arrowhead, before tossing it into Malivore.
- People Puppets: Hope uses a basic mimic spell to force Clarke to copy her movements exactly. She then leaps into Malivore, taking him with her.
- Resurrective Immortality: Both Landon and Clarke come back after being killed. Clarke simply gets up a few minutes later, snapping his neck back into place, while Landon burns up and rises from the ashes.
- The Reveal:
- Alaric has a contingency plan to deal with the students in case they ever got out of control. Unfortunately, MG's mom is aware of the plan and makes use of it to capture the school.
- Malivore plans to use Landon as its host and to create a new race of half-golems.
- Clarke was lying about wanting to repent for getting Malivore turned into a puddle. He still hates his father and was only trying to break him out of his prison because he was afraid of him returning on his own. He was more then happy to let Hope sacrifice herself to destroy the golem permanently.
- Alaric has been hiding some kind of object in his office in a mirage of books on a shelf. Thanks to the Anti-Magic artifact, the spell was temporarily lifted, allowing the twins to find it. Josie swipes the object, assuming it may be related to the Merge. While the twins are unaware of what it is fans of The Vampire Diaries will know that it is the Ascendant, the key to a Gemini Coven prison world that their Evil Uncle Kai Parker is trapped in.
- Ret-Gone: Hope is erased from people's memories after leaping into Malivore. She asks Alaric to burn all files on her prior to that, as she doesn't want to leave any trace, although she insists that he leave himself a note that he has to come and get Landon. Kaleb and Josie are left wondering why they have five voting stones when there are only four people on the honor council.
- Season Finale
- Secret Legacy: MG learns that his mother's side of the family has been a part of Triad for centuries. He tells her that if this is his family legacy, then he doesn't want to be a part of that family anymore.
- Take That!: Landon makes one to Tim Burton after he and Hope defeat the Headless Horseman.
- Taken for Granite: Burr is about to shoot MG when Nia shows up and turns him to stone.
- Taking the Bullet: When Burr is choosing which of the girls to shoot, Lizzie is about to jump in front of them, only for Josie to beat her to it. Fortunately, Hope's blood is enough to save her.
- Taking You with Me: Hope leaps into Malivore to destroy it, but not before using a mimic spell to force Clarke to jump with her.
- Talking Is a Free Action: Clarke demonstrates that it's not by taking the arrowhead, while Hope and Landon are busy professing their love for one another.
- Title Drop: Said by Hope to Landon as she's trying to figure out a way to destroy Malivore.
- Wait Here: When going to infiltrate the school through a secret tunnel, Alaric tells Dorian to wait for him at the car, likely unwilling to let Dorian learn about the tunnel and the Anti-Magic artifact. Naturally, Dorian doesn't listen and saves Alaric from a Triad soldier. Instead of being angry, he immediately agrees to give Dorian the raise he asked for in the previous episode. Dorian counters that he is getting the raise with dental.
- Weapon Specialization: The Headless Horseman uses a bone whip as its weapon. After the Horseman is dead, Landon uses the whip to snap Clarke's neck, which is impressive, considering it's first time he's using it.
- Would Hurt a Child: Not only is Burr perfectly willing (nay, gleeful) to hurt and kill any of the teenage students, he also aims his gun at one of the little ones, just For the Evulz. It's clear he doesn't consider them human.
