Wolfblade (4) book 4 of the SpaceWolfs ( warhammer 40k )

The ancient Navigator House of Belisarius has long been bound to the mighty Space Wolves as allies. In return for the means to navigate the treacherous warp, the Space Wolves provide an honour guard of elite warriors - the Wolfblade - to protect the house. When Ragnar takes up his duties on ancient Terra he soon becomes embroiled in an assassination plot that reaches into the very depths of the Imperium! Unused to delicate political machinations, Ragnar must resort to the howling fury of the Wolves if he is to save this noble dynasty and regain his honour!