Books with a fairly standard plot rely on their characters to see them through. Unfortunately in the case of Predator X, author C.J. Waller puts a bunch of whiny, annoying characters without much substance through a very standard subterranean horror scenario. The result is something which has its moments - with a second act change of direction especially welcomed after a patience-straining beginning - but which overall never managed to truly engage or make me care.
2.5 Things Worse Than The Dark for Predator X.