The protagonist (Paddy Considine) is a man tasked with looking after his friend Imogen's house, and is instructed to take her dog Rothko for walks, but not to let him off the leash.

After putting Imogen's keys through the mail slot in her door (so they do not get lost), the man ensures that he will not lose Rothko by tying the dog's leash around his own neck.

The man recalls a time where he was spoken to similarly by a gerbil as a child, telling him his father was cheating on his mother.

In a closing monologue, the man reveals he left a note to Imogen apologizing for the keys and dog, and imagines her being satisfied with it, but he is sure she is not.

A couple of actors featured in Jam appear in cameo form and uncredited - Mark Heap is seen as a park warden, while Kevin Eldon is the man's father in a flashback.