The Deadly Dare Mysteries
Publisher: Random House
This is a bind-up of three books - Deadly Dare, Computer Ghost and Lie Detectives, all featuring best friends Theo and Ricky.
In the first book, a game of dare gets seriously out of hand when Ricky goes missing, and ends with an armed raid on a museum. In Computer Ghost, Theo and Ricky form a detective agency, which gets its first case when a series of desperate emails are sent to their friend Jade - apparently by the ghost of her dead father.
In Lie Detectives the friends make their own lie detector and try to solve the mystery behind the near death of a top inventor.
Ultimately these stories work because they play on the fantasies children have of being heroes and solving mysteries.