Sooty and Soo are deciding what pet they would like. Sweep suggests a dog, but Soo isn't so keen. Matthew wants a dog and teases poor Sweep, who thinks he has to move out. Sooty, Sweep and Matthew go and see some police dogs in training and Matthew sings "A Dog Is A Man's Best Friend". Then Matthew decides they'd rather have Sweep than another dog, because he's very special and one of a kind.