Mrs Tachyon and the Bags of Time

The hero, Johnny Maxwell and his friends: Yo-less, Kirsty, Wobbler and Bigmac, find the local tramp/bag lady injured. While she is taken to hospital they are left in charge of her trolly full of dustbin bags. These bags turn out to be full of time and soon Jonny and friends find themselves in the 1940s during World War 2.