'I heard a murder being planned.'
Scarper Jack is inside a chimney when he overhears the voices. He knows where and when a murder is going to happen - but there's no way he can stop it. He's only a chimney sweep's boy.
With the help of two unexpected friends - a posh boy and a sewer rat of a girl - he sets out to solve the mystery and track down the murderer.
Only to find that it's dangerous to know too much...