Trouble in Time
Check out Adele's blog:
"Twelve-year-old Ben Jackson resents being thrown out of his room to sleep in a shabby caravan when his Mum’s Poppa, George, comes to stay. Ben finds his great-grandfather sullen and grouchy, while 91-year-old George thinks Ben spends too much time on the computer. At first, the generation gap seems impossible to bridge - until the unthinkable happens. Ben is thrown back into 1934 with George (as a boy) in his home town of Marshville"