Toys go missing, of course, in a house with six children. It's as natural as apple pie and ice-cream. It's a different matter when they start appearing.

When beautiful old toy soldiers-just like the ones in the antique shop down the road-start popping up on Mary Frances' bedroom window-sill, her search for clues to the curious figures leads her to a wider mystery. Things aren't where they should be. Or, perhaps, they aren't when they should be. Either way, Mary Frances and her sister Annie are going to need all the help they can get to solve the mystery.

That help comes to them unexpectedly in the form of Thunderpaws, a mysterious orange cat with remarkable abilities. With Thunderpaws guiding them, Mary Frances and Annie learn to slip into the space between the lightning and the thunder and emerge into a place that looks a lot like home. Here, too, there are things going missing and other things appearing that don't belong, and a wandering man who might hold the key to the whole affair.

The girls meet young boys Evan and Johnathan (who live in a suspiciously familiar-looking farmhouse), and the four children must band together with an elusive group of time-travelling orange cats to put everything back when it belongs.