When Eep wants alone time with her new friend Dawn, Guy seeks a new friend of his own and finds an unlikely companion in Thunk.

When the Bettermans invite the Croods to join their family game night, two things become clear: Phil needs to win and Grug hates to lose.

After a crowverine gliding mishap, Dawn loses her confidence and tells Eep she's taking a break from adventures. Eep convinces Dawn to join her on one last adventure – climbing Grrr Mountain.

When Hope oversteps by trying to teach Sandy manners, Ugga gets her revenge by challenging Hope to do the impossible: civilize Thunk.

Ugga has a secret - she's taking Eep to "flop with the bulrusses" - a fun and dangerous pastime Ugga enjoyed as a teen. Ugga's excitement fades when Hope invites herself and Dawn along.