Every Thursday at midday Audrey Brooks cleans the Petrov house.

Mr Petrov is never home - in fact he seems to use the house purely as storage for his impressive collection of antiques - but that doesn't affect the care with which Audrey mops, polishes, and carefully winds each of the dozens of beautiful clocks that decorate the tall, elegant, empty London mansion. Until the morning she finds a corpse in the back bedroom, the pristine walls and floor covered in blood, and flees the house in panic. Fifteen minutes later, the police arrive...

and find nothing. No body. No blood.

The only thing slightly out of the ordinary is the clock in that back bedroom, which is now running four minutes slow. With no victim, the police are convinced there was no murder, but Audrey knows better. A man has been killed, and if they won't do anything about it, she - and her annoying friend Lewis - will.

Whodunnit is one thing, but this detective duo must also wrestle with when - and where on earth is the body? It's not long since they solved the murder of their neighbour, so they're not rookie sleuths, and at least this time the case has no connection to their home. Does it?