Short but very recommended. It's the story of a group home that takes in ex-magical-children, the kids who have wandered through the backs of wardrobes, gone down garden holes, stepped through secret doors, etc, into alternate magical lands. There are hundreds of stories about the children who go to Narnia but no one ever talks about the ramifications on them when they come home, or how they adapt. This is that book, a story about thoroughly messed-up kids who spend their days pining to go back to their own particular magical world (and spend their nights searching the school for hidden doorways or any other gate that might let them back in) as they are slowly and painfully re-adapted to "normal" life here and now. The worldbuilding is fascinating, with all the study of the compass of alternate worlds... Is this child from a High-Fantasy, High-Logic world or a High-Fantasy, High-Nonsense world? The lingering effects on the children are equally fascinating, whether they keep trying to cast spells that no longer work, keep trying to turn invisible, or engage in constant struggle with their own bodies (What DOES happen when you go to the Kingdom of Goblins, kill the Goblin Leader with a magic sword, reign for 12 years in his place, and then one day accidentally step off the wrong path to find yourself back on our earth, and back as a ten year old once more?) 
 The first half of the book is devoted almost solely to introducing the characters and their histories, while the latter half brings us into a mysterious spate of murders occurring at the home. Eventually the kids have to team up to solve the mystery, but the team of psychologically broken ex-"Chosen Ones" is about as far from Scooby Doo as one can get. 
 A great book. Sad, wistful, thought-provoking, and original - and very well written. It's also worth mentioning that while this is first in a series, it's a complete story with no "To Be Continued" or anything to spoil the ending. The setting and concept are wide open enough to let a hundred more stories be told with the same concept. Definitely recommended!