The Trollhunters are in search of Merlin's tomb and the Staff of Avalon, but with Gunmar already ahead of them it might be too late.
- Anti-Magic: No one can use magic of any sort while in Merlin's tomb. Even any currently active spells are disabled, such as Gunmar's control over Draal.
- The Bad Guys Win: Gunmar succeeds in getting the Staff of Avalon.
- Call-Back: "Take it. Don't make it weird."
- Continuity Nod: The story Strickler tells Claire's parents and Toby's Nana is the dinner date from "Recipe For Disaster", mentioning the absurdity of their fight while Barbara was not looking.
- Cool Key: The stone in the Amulet is the key that brings the ancient gyre to Merlin's tomb.
- Death Trap: The trap Gunmar left AAARRRGGHH!!! in has dozens of live dwärkstones trapped with him in a stasis trap. They deactivate it and they destroy them and the rest of the temple with them.
- Foreshadowing: At the beginning, a feminine hand with gold claws on it melts into the pot with he contents of what would eventually become the Amulet of Daylight.
- Hand in the Hole: They find Draal's mechanical hand used to wedge the entrance into the caverns open.
- Heroic Sacrifice:
- In order to find the Tomb Jim has to destroy his amulet.
- Draal is killed when he uses his body to stop Angor Rot from stabbing Jim.
- Noodle Incident: Somewhere in-between the Trollhunters teleporting to the temple and their activation of the ancient gyre, Strickler and NotEnrique arrive to the Lake household, Claire's parents and Toby's Nana having already gotten used to them (showing no surprise at his true form either) and are already having a casual conversation about the time he and Jim fought behind Barbaras back.Strickler: So there Jim was, sword to my throat, then Barbara comes out of the kitchen with a pie! Jim and I looked at each other and I say, "Where is that contact lens?"
- Pet the Dog: When Gunmar tells Draal "You are a dog and this is your leash!", Angor Rot remembers when Strickler said the exact same thing to him and convinces Gunmar to spare Draal. This is Foreshadowing for his nobility returning now that his soul is back.
- Portent of Doom: The illustration on the wall beyond Merlin's workshop illustrates the future, display an illustration of Jim, Toby and Claire, as well as Angor Rot.
- Shoo the Dog: Played for Laughs.Blinky: Stay here. You're my brother. And I still don't trust you.
- Throw the Dog a Bone: After being defeated several times and even made his slave, Draal finally wins a fight against Gunmar. Sadly it is a short lived victory.
- Time Travel: Merlin's old workshop has a stone on the floor that, when pressure is placed on it, the entire room reverts to how it was centuries ago.
- You Have Outlived Your Usefulness: Gunmar leaves Angor to his fate after getting the Staff.