With the trolls hiding out in Arcadia, AAARRRGGHH!!! goes undercover to see what Gunmar is up to. A potential rival brings out Jim's jealous side.

Toby gets caught in the crosshairs when a troll goes missing and the city cracks down on crime. An ancient voice refuses to be silenced.

Something strange is brewing at school, where the teachers are more agitated than usual. Claire's illness shows disturbing side effects.

Toby and Darci ask Jim and Claire on a double date. Gunmar returns from his travels, now armed with the knowledge to bring forth the Eternal Night.

While Gunmar searches for the Staff of Avalon, Jim and Toby head into the Shadow Realm to rescue Claire's spirit and return it to her body.

When Barbara's art obsession leads to an "aha!" moment, she demands Jim tell her the truth. Dictatious reveals Gunmar's plans to resurrect Angor Rot.

With the future of two worlds at stake, the team races to find Merlin's Tomb -- and the Staff of Avalon -- before Gunmar can get his hands on it.

A long-dormant ally shows Jim and his friends what really happened at the Battle of Killahead. Gunmar awakens Morgana, and Angor Rot plots his revenge.

Merlin has a plan to go to war, but it's Jim's choice to make. Blinky and AAARRRGGHH!!! search for allies. Gunmar uses Barbara to get what he wants.

A greatly changed Jim renews his Trollhunter training but struggles to accept his new reality. Gunmar and Morgana rally the troops for an attack.

The Eternal Night covers Arcadia in shadow, leading to a long-awaited showdown between Gunmar and the newly transformed Trollhunter.

An epic battle comes to a head in the darkness as Jim and his friends push back against Morgana. But without Merlin, how will they stop her?