Raven's Gate book 1:

Matt has always known he has unusual powers. Raised in foster care, he is sent to Yorkshire on a rehabilitation programme, only to find himself in the midst of sinister goings-on. Matt investigates and uncovers a terrible secret - eight guardians are protecting the world from the evil ones, beings banished long ago by five children. But devil worshippers want to let the evil ones back in. As the story reaches its climax, it looks like Matt has succeeded in stopping them ... or has he?

Evil Star book 2:

Matt thought his troubles were over when he closed Raven's Gate . . . but in fact they were just beginning. His fate -- and the fate of the world -- is tied to four other kids across the globe. The second is a street kid in Peru. He and Matt have never met; they don't even speak the same language. But destiny is going to throw them together as the evil threat of the Old Ones grows . . . and another Gate suddenly comes into play. Another masterful thriller from supernaturally suspenseful Anthony Horowitz.

Nightrise book 3:

Nevada, USA - fourteen-year-old twins Jamie and Scott Tyler are performing a mind-reading act in a dingy theatre. But when a sinister multinational corporation, Nightrise, kidnaps Scott, Jamie is left alone - and wanted for murder. He becomes embroiled in a corrupt presidential campaign and breaks into the American prison system before being propelled ten thousand years into the past, where he encounters the other Gatekeepers and witnesses the creation of Raven's Gate - and the first fateful battle against the Old Ones.