Bob and Scoop discover some old bones in a ditch at Farmer Pickles' field. While Bob is out at the museum, Spud persuades Scoop to see some bigger bones that he found. Mr. Ellis thinks that a stegosaurus skeleton was found, but some of its bones are missing.

Bob discovers a porcupine asleep in Farmer Pickles' cottage and Scoop takes it back to the yard, while Roley looks after it. But when Farmer Pickles arrives to see Wendy, Scruffty jumps out of Travis' trailer and he and Pilchard chase each other which makes Roley worried that it might wake the Porcupine.