What if the world outside that they thought was safe suddenly becomes extremely dangerous due to a new natural phenomenon? Eep and Guy have to lead the Croods family to find a new place to live. But on the way, they find out that the danger was caused by something Guy unknowingly did in the past. He feels guilty, but Eep stands by him and together they find a solution to fix the problem and save their family.
Perhaps Eep has a special power that she discovers suddenly. This power is something that no one in the Croods family has. Guy helps her understand and control this power. But as she gets stronger, some of the Croods start to fear her. Guy has to convince them that Eep is still the same person, and they all learn to accept this new side of Eep.