Fear by Micheal Grant

In the book ‘Fear’, Sam and his group of survivors in F.A.Y.Z have a very, very big problem, the F.A.Y.Z dome is turning black and it’s thanks to the ‘Darkness’. However, the only way for Sam to stop the darkness growing is by killing the Darkness itself, but this leads to a big finale in the last book of the series, 'Fear'. Along with the Darkness being a big problem, the almost invincible Drake, still roams free and Sam has to stop him before it's too late.