12-year-old Finn Spencer is not the sort of boy who writes in a diary or is he if it can change the past? On a visit to the funfair with his little sister, Finn is given a diary by a fortune teller and decides to write in it. After all, he intends to be famous one day and will need to remember all the things he did for his memoirs!
He soon realises it's not a normal kind of diary – it can change the past! So when Finn writes what he should have done that day, rather than what he actually did do – what he should have done is what everyone remembers. To start with, it's great but then things go wrong as he tries to find out what the diary can and can’t do for him.
Some things work out really well for him, like £5 from his Granny and winning the talent show but there are downsides too. Finn falls out with his best friend and has to go to a concert with his sister.
Can Fin control the diary, or will it control him?
