When Cavey Jr.'s school refuses to teach evolution, Captain Caveman turns to Harvey to defend the hairy little boy's right to an education. Harvey not only has to prove evolution but also explain the existence of a talking caveboy.

Birdgirl's back with a new case for Harvey; Race Bannon and Dr. Quest want to form a legal partnership. Unfortunately for Harvey, the case goes to the highest court in the land, the Justice League. In the meantime, Phil has set his sights on Birdgirl.