Dead Sky, Black Sun: Pt. 3 by Graham McNeill
Hard-hitting SF action with the superhuman Space Marines and Captain Uriel Ventris. Exiled from his Chapter, Uriel ventures deep into the dreaded Eye of Terror to confront the terrible foes that dwell within these worlds of insanity. Chief amongst them are the ancient Chaos Space Marine legions - twisted warriors who have allied with the Dark Gods and are set on humanity's destruction.