Fireman Trevor Evans tells the children that there's no such thing as little green men from outer space, but Norman Price is determined to prove him wrong. Fireman Sam and Cridlington come to stop him in his antics.

Mandy Flood, Sarah and James decide to start a junior neighbourhood watch scheme, but get rather carried away. They suspect Trevor Evans of stealing Dilys' fruit and veg, only to find that he's delivering it. Then they mistakenly administer first aid to Bella Lasagne before discovering that she's covered in ketchup, not blood. Finally they clear away an 'unattended' ladder, stranding Mike on the roof of the cafe.