Raven's Gate
It is followed by "Evil Star" , released in 2006 , "Nightrise" in 2007 , and "Necropolis" in 2008 , with the final book "Oblivion" in 2012 . 
<triplet> Evil Star <subj> Nightrise <obj> followed by <triplet> Nightrise <subj> Evil Star <obj> follows <subj> Necropolis <obj> followed by <triplet> Necropolis <subj> Nightrise <obj> follows