Malcolm "Mackie" Doyle is a very strange teenager. He tries to fit in, but can't. He's known as a weird and creepy boy who is very pale, blond-haired, and dark-eyed. Mackie is allergic to iron. When he sees blood, he becomes very ill. He tries his best not to bring attention to himself for reasons that are accepted but not really stated. The town of Gentry, where he lives, is almost as strange as Mackie.

Mackie also hides a dark secret, one his parents and sister hide from the world. They even keep the most important facts from him. Mackie knows he's not normal, but no one will tell him why. That is, until one of Mackie's schoolmates, Tate, experiences a family tragedy. Tate's little sister, Natalie, has been killed, or I think she has been killed, but again, everyone seems to dance around the situation that has occurred. Tate knows her sister's death was due to an evil influence, but finding the answers will be very difficult because everyone around her ignores the signs and pretends that nothing is wrong. However, Mackie is getting closer to the truth about himself and Tate's sister.

Mackie replaced the real Malcolm Doyle when he was only a baby. He's known as a Castoff and was expected to die, but instead he thrived. Now the creatures of the underground, the ones that have jagged teeth and ugly features, want Mackie to join them. If he doesn't, he will continue to weaken. His sister Emma will also suffer, for she was the one who was able to save him from dying when he was only a baby.

THE REPLACEMENT is a very dark and strange book with which I could not connect. I felt no connection to Mackie, his predicament, or the spooky atmosphere. Though it started with an interesting premise, ultimately the story felt superficial and hollow. This book may appeal to some readers who enjoy the macabre; unfortunately, I am not one of them.