The Switch book by Anthony Horowitz

A dark and mysterious adventure from the number one bestselling author of the Alex Rider series. A boy’s casual wish leads him into a dark and mysterious world in this thrilling adventure from the bestselling author of the Alex Rider series. For Tad Spencer, only son of a fabulously wealthy businessman, every day is like Christmas.

Until he makes the mistake of wishing he was someone else. The next morning he wakes up as Bob Snarby, trapped in a cruel and squalid funfair world inhabited by hopeless criminals, mysterious fortune tellers and – worst of all – the murderous Finn. But he’s there for a reason, as Tad discovers when he begins to untangle a secret that will introduce him to the most unexpected enemy of all…