Warhammer 40k the Chapters Due

"(W) Graham McNeill The new Ultramarines novel! Having defeated the forces of the tau on Pavonis, Captain Uriel Ventris returns to Macragge. But war is unending in the life of a Space Marine, and Ventris finds himself thrust back into battle against the nemesis of the Ultramarines - the Iron Warriors. Will Ventris be able to overcome his greatest test to emerge victorious, or will the Ultramarines suffer a defeat from which they will never recover?"