Caveboy and Cavegirl are best friends. They even share a birthday. Each wants to get the other something special for the big day so they go shopping at Caveman Collectibles for just the right thing. But neither has money enough to buy a present for the other. So Cavegirl trades her beloved tool collecti on for a box to give to Caveboy to store his rock collection. Likewise, Caveboy trades in his cherished rocks for a box to give to Cavegirl for her tools.