Ben Counter
The Grey Knights Omnibus

Even by the standards of the Space Marines, the Grey Knights are a breed apart. Only they can hope to stand against the infernal foes of mankind, the daemons of Chaos, and defend the Imperium from the corruption they wreak…
Warhammer 40k
omnibus

It contains:
Dark Adeptus
Grey Knights
Hammer of Daemons

Also in:
Grey Knights Digital Bundle