The Stalkers are strange beings that start menacing Aidan Cain shortly after the death of his grandmother Adela Cain. Some of them are golden and tall and look like warriors. Others are short and alien, and still others call him in alluring voices. They always seem to know exactly where he is, too. Luckily, they always got the name wrong when they tried to lure him to follow them. And they got into fights with each other, loud enough fights that the foster family he's assigned to can hear the fight noises, and assume it's cats fighting.
Aidan, however, knows exactly what they want -- they want to kill him. And he's very frightened. He doesn't know why they are after him, and yet he's sure they can't get him when he's inside a building, or during the daylight. After the night of fighting noises, he makes up his mind to leave, and runs away as soon as it's daylight, telling only his foster siblings there what he's doing and why.
Aidan makes his way to Melstone House, the place his grandmother has told him to take refuge if he finds himself in danger after she is gone. And there he finds an ally in Andrew Brandon Hope, the new owner. Andrew believes him about the Stalkers, but determines to go to London to see what more he can find out about both the official groups (police and/or social workers) and the magical ones who are after Aidan.
When Andrew visits the foster family, he can tell quite quickly that they've made up stories to explain away the disappearance of one of their foster children, and he doesn't disabuse them of that. As he's leaving, though, one of the stalkers appears to him directly -- tall, goldish in color, with a purplish cape, or possibly wings, down its back, and a helmet with high pointed side pieces curling up over its cheeks. It almost compels him to tell where Aidan is, but it uses the name Adrian, just like the foster parents do, which saves Andrew from being forced to tell it. It explains that it is one of the King's men -- and when asked what King it's talking about, it says "Oberon, of course."
Foreshadowing many more problems to come....