Where you are needed (слэш)

In modern day London, Tom finds a dark-haired boy lying unconscious in the snow in front of his Children's Home. The circumstances of his appearance are suspicious to say the least, just as the fact that the boy doesn't remember anything apart from his name: Harry.
How can this boy resist his powers? What was this green light when he appeared out of nowhere? Why does he seem to know more than he should? Tom is determined to pierce the mistery of Harry, but if he's not careful, he might find more than he bargained for.