Summary from GoodReads:
What a nightmare.
Hannah Dias, California Girl with Attitude, and Alex, her laid-back brother, have moved from exciting San Francisco to boring Snipesville, Georgia. Life doesn't improve when they meet Brandon, a dorky kid who is plotting his escape from the Deep South, and the weird Professor, who has a strange secret.
Suddenly, the kids are catapulted thousands of miles and almost seventy years to England during World War Two.
They fall into a world of stinging nettles, dragon ladies, bomb blasts, ugly underwear, stinky sandwiches, painful punishments, and non-absorbing toilet paper. They learn so much more than they could ever learn in a history class. Not that they want to learn it.
But they can't go home unless they find George Braithwaite, whoever he is, and whatever it is that he has to do with Snipesville.