Fireman Sam introduces Sarah and James to his new metal detector, and they get hooked on looking for treasure. Unfortunately, they manage to burst a water pipe in the park while searching for Bella's keys. Norman Price's game of "Knights of the Round Table" backfires when his saucepan helmet gets stuck on his head. Overall, it's a busy day for Fireman Sam and the crew.

Fireman Sam's mislaid his watch, Bella's necklace has disappeared and Dilys' earrings have gone missing. Can Sam solve the mystery? Then there's a chimney on fire at Bella Lasagnae's Café and Fireman Sam comes to the rescue.