The story of an Old West town being scared by a Therizinosaurus ends with Deputy Hannah saving the day; Trek investigates why herbivores stick together in a giant migrating herd.

Ms. Carver's class gets a new addition in the form of mystery eggs, and Dan just knows one of them is a dinosaur egg! When Trek and Tristan find a bone in the schoolyard, Dan uses a papier-mâché skull ...