Ravenwing (Legacy of Caliban #1) (Warhammer 40,000)

The Ravenwing stand apart from the rest of the Dark Angels Chapter - these dynamic Space Marines take to the battlefield upon steeds of adamantium and plasteel, and swoop from the skies in lightning-fast speeders to bring death to the foes of the Imperium.

When he joins their prestigious ranks, Brother Annael finds himself thrust into a whole new world of shadowy intrigue, and privy to secrets unknown to his common battle-brothers. In the wake of the conflict at Kadillus, hints of a dark conspiracy begin to emerge, and it soon becomes apparent that the Ravenwing has a sacred duty far more vital than hunting down orks...

Read it because

It's a fast-paced action-adventure tale that pits the Dark Angels against greenskins, pirates and Chaos Space Marines and lays the groundworking for the mind-bogglingly epic drama to come in the rest of the trilogy.