When Chomper loses a tooth, he becomes afraid that his entire body may fall apart. Meanwhile, Cera is disappointed to discover that her special outing with Tria is a trip to a mud pool.

When a relentless rainstorm destroys Petrie's nest, Petrie freaks out at the prospect having to move to a new nest. Meanwhile, Cera insists that Ducky take on the seemingly impossible task of teaching baby Tricia how to swim.

When adventuring in the caves, the group accidentally goes into the Mysterious Beyond and get chased by Redclaw, Thud and Screech. An earthshake occurs, and Chomper and Ducky get trapped with Thud.