The complete history of the Gothic Sector War. Covering Abaddon the Despoilers attempts to gain control of the various Blackstone Frotresses from the Imperium of man. The Battlefleet Gothic of the Imperial Navy and the Forces of Chaos fight a massive war for the Sector drawing in the Xenos races of Orks and Eldar, as well as many others.
Ties in with my recent readings of Execution Hour and Shadow Point by Gordon Rennie which covers these events by following the crew of the Lord Solar Macharius under the command of Commodore Leoten Semper.