Tirion flies Flint, Alexia, Zeppo, Albert, and Ruby to the Star Key to confront Mephisto. Flint makes his way through the dungeon and he finds that Zeppo has been captured. Mephisto appears and inserts a key into Zeppo, also turning him into a mechanical monster. Flint defeats the monster, returning Zeppo to his former state, and then faces Mephisto in battle. Flint kills Mephisto and the Star Key collapses into the sea. The group escapes on the back of Tirion; Flint and Alexia share an embrace as they fly away.