The mystery of the mechanical sparrow

Teenager Sophie has just lost her father and is starting a new life as a shop girl at Sinclair's, a lavish London department store, where she soon befriends the dreamer Billy and the charming Lil. But then, priceless jewels are stolen, including a remarkable mechanical sparrow. And suspicion falls squarely on Sophie. When she overhears a conversation with the head of London's criminal underworld, she decides to uncover the truth with Billy and Lil – and with the help of the runaway Joe, they embark on an investigation that takes them further than they ever imagined.