Raven's Gate by Anthony Horowitz

I just Finished Raven's Gate and it was a good fantasy story. I don't normally read fantasy, but I enjoyed Horowitz's Alex Rider series so much I wanted to try something else by him. The main character's name is Matt and he is caught after trying to steal DVDs from a warehouse. This gets him put into a program called the L.E.A.F Project where he will be sent to live with a family for a while and help them out and go to school. He is assigned to this woman named Mrs. Deverill who lives outside of the town of Lesser Malling on a dingy farm. She is mean and makes him work all the time. Matt wants to escape but can't figure out how. Then strange things start happening. Matt wakes up in the middle of the night hearing chanting and sees a glow in the woods. What is going on? He tries to find the source and comes across an old abandoned nuclear power station called Omega 1. What does it have to do with what is happening around him? Why does Mrs. Deverill want him? She obviously doesn't like him but she won't let him leave. Is there any way Matt can escape or will something awful happen before he can?