Xandra Hobson has always been fascinated by magic. So when she rescues a beautiful wounded bird, she is convinced that the glowing white feather it leaves behind must be magical. When she brings the feather to school, she is surprised to find that Belinda is interested in it, too. Belinda is a weird girl whom everybody makes fun of. Xandra doesn’t want to be seen with her, but Belinda seems to know something about the feather—so Xandra decides to befriend her. Belinda calls the feather a key.But a key to what? And how does it work? When Xandra tries to use the key, she becomes aware of an unseen world, full of phantoms. Some are soft and cuddly, like the young animals she has rescued. But others are terrifying monsters. Could the key’s magic be evil? Xandra needs Belinda to help her explore the unseen, but she also needs to learn to help herself if the key is to become a gift and not a nightmare.