Frozen in Time, by Ali Sparkes (Egmont/Random House, 2009 in UK, 2010 in US, middle grade, 312 pages).
Rain has kept Ben and Rachel trapped inside their old house on the far outskirts of a small English town. It has also washed away a secret--when it finally clears up, the kids find the sealed hatchway to an underground vault. Despite their (perfectly natural) misgivings, they climb down and begin to explore the hidden rooms, finding a time capsule of 1950s life. Literally-as well as tins of vintage spam, there are two kids down there. Rachel unwittingly sets in motion the mechanism to bring them back from their frozen un-life....and then the fun begins.
Polly and Freddy were sealed in their cyronic chambers by their scientist dad, back in 1956. Then he disappeared, before he could wake them again. It seemed as though he had murdered them, and perhaps defected to Russia...but Polly and Freddy are proof he didn't do the former, and they refuse to believe he would have done the later.
Now the two modern kids have to instruct the two 1950s kids in all the niceties (or not) of 21st life...and all four must use their wits to find out what really happened to the lost scientist. Because Polly and Freddy's reappearance is sending out ripples in the hush hush world of government agencies...and the ripples are attracting sharks.
In large part this is a straightforward, fun adventure, in which considerable time is spent on the fun and games of time culture shock. Imagine the kids from The Famous Five (Polly was reading them, back in the past, as fast as they were published) showing up in your own kitchen, with their outdated attitudes toward gender, and their understandable confusion at linguistic and technological changes. Imagine Polly and Richard's confusion, as they were asked to share the very bedrooms that had been theirs the day before...over fifty years ago....
And then imagine Russian spies, and the like, closing in. While over the heads of the four children hangs the mental image of what happened to the father's other experiments--the rats who had died, bleeding and blinded, after long experimental spells of cyronic sleep. The parents aren't around to save the day (Ben and Rachel's old uncle has gone off to pull strings in London) and the school bullies must be out witted! Will it be a jolly good show, or something...else.
Time travel wise--lots of points for good time culture shock, nicely balanced with the progression of the story. The time travelling kids were allowed genuine moments of emotion, before their stiff upper lips kicked in, and they were allowed to adapt at what I thought was an acceptable pace--neither blind acceptance of everything, or too stubborn a refusal to grasp what had happened.
In short, a fun, fast read, good for light, rainy day escapism. That's the English cover at right--I like it better. It looks less cheesy; the US cover has a very dated look, to my eyes.