Graham McNeill
Forges of Mars

A great explorator fleet sets out into uncharted space, the Halo Worlds at the galaxy's edge. They seek an ancient and priceless technology from the birth of history, but what they find is more powerful and deadly than any of them could have imagined.
Warhammer 40k
omnibus

It contains:
Gods of Mars
Priests of Mars
Lords of Mars
Zero Day Exploit