When Dana visits, Dex convinces her and her friend Riley to play her old DIY board game "Game of Bones" with him and Kayla. But this time, instead of dinosaurs, the players must choose a prehistoric mammal to see who was built for survival.

In part one of the Dino Dex season finale, Dex and Kayla need help taking on the Colossal Squid, Megalodon, and Albertonectes in their time-bending submarine. It's clear who they should bring in but, when Dex doesn't want to call Dana, it's up to big sister Saara to find out why.