It is Earl and Fran's 20th wedding anniversary, the Graptolite anniversary. Graptolites are the sweetest-tasting and most adorable little animals, but they are also quickly disappearing from the earth. Earl has acquired the last pair before they become extinct, and everyone else wants them, particularly his boss Mr. Richfield. Robbie befriends the creatures and finds they are the very last pair. Soon, father and son are at each other's throats over the fate of the Graptolites.