Well, this was a yawner. Hard to believe Stephen King co-wrote this. It just read like ... not a lot of thought went into it.

A Mysterious Man gives a 12-year-old girl named Gwendy a box with eight buttons on it. Each button represents a different continent, with two additional buttons for when Gwendy wants to use her imagination (trying not to spoil here). The box affects Gwendy's life even when she doesn't touch it.

There's a stereotypical Bad Guy who sounds straight out of a teenage angst 60s film, there's a stereotypical Perfect Boy who is given zero personality, and the whole thing is pretty predictable except the end, which is honestly a let-down. Can't recommend.