Thunderstone (1999)

With the Shadow Master and his minions defeated, Noah stays at North Col but misses Haven and is tempted to go back. When he does, he becomes stranded since there is no longer any thunderstone left, or so it seems. In this season, the plot revolves around acquiring a large Thunderstone Cube, which Noah learns about from fugitives from the future, named Mayah and her brothers, who brought it there under a lake.