After discovering a new cut price supermarket, Vince becomes rather keen on its own brand energy drink Blue Rat - all the energy of a rat trapped in a can. Meanwhile Errol realises one of his life ambitions of working with fish.

Vince falls for Stacey, the aqua aerobics instructor at the pool where he works as a lifeguard. Stacey thinks Vince is a bit weird until she sees his medical notes. Meanwhile, Errol has his own problems. He agrees to take part in a swimathon in aid of sick kids even though he can't swim. Vince decides his flatmate needs to conquer his phobia of saying "no".

Car-boot sales, pigeon droppings, illegal substances and ping-pong enthusiasts may, to the casual observer, seem somewhat unconnected. However, all four seemingly disparate elements converge in one day, resulting in quite an eventful and particularly miserable time for Vince.