Frozen in Time by Ali Sparkes
1956 Freddy and Polly have always known their father is a genius. So they've never minded helping him with his experiments. Even when that means being put into cryonic suspension-having their hearts frozen until their father wakes them up again. They know it will only be for an hour or two, so there's nothing to worry about...2009 Ben and Rachel have resigned themselves to a long, boring summer. Then they find the hidden underground vault in the garden-and inside it two frozen figures, a boy and a girl. And as if that isn't spooky enough, when Rachel accidentally presses a button, something unbelievable happens...Can Polly and Freddy adapt to the twenty-first century? Will their bodies survive having been in suspension for so long? And most important of all, what happened to their father-and why did he leave them frozen in time?