When Hiccup discovers Trader Johann's ship was shipwrecked in a rumored haunted bog with a gift made for him by his mother, he will stop at nothing to retrieve it -not even being followed by a "fog monster".

During Berk's annual Bork week celebrations, Hiccup is granted access to Bork the Bold's private and personal archives. When he finds information and a map about an island inhabited by Night Furies within Bork's notes, Hiccup is determined to bring Toothless to his family. After discovering that the Bork notes are fakes made by the Outcasts, the duo tries to flee, but are captured by Alvin.