While exploring Rocko's old home, Filburt's sons, in the future now grown up, find a banana in the fridge. They go to their father, now aged, to explain the story behind the banana in the fridge. In flashbacks, we learn that Conglom-O had put Ed Bighead in charge of a experiment monkey. Rocko and Heffer found out, and tried to save the chimp. (thetvdb.com)