And the Siege continues. Warhawk by Chris Wraight (2021) takes the conflict to the next level. In Mortis, traitor forces pushed hard on the walls of the Emperor's Palace and breached the Lion's Spaceport. Honoring an oath, Jaghatai Khan rallies the White Scars for a counter-strike; the port's role is critical to Loyalist plans for stopping Horus. But Horus has other plans.
Warhawk follows a handful of sub-plots. Primary is Khan honoring his promise—or at least trying. The second is a secret Loyalist plan to refurbish a destroyed space platform and use it as a battle station. In a third, Mortarion and the Death Guard close the open threads of The Buried Dagger—coming to terms with their bodily changes due to Chaos. Further plot points still, Imperial Fist Sigismund gets a new sword that seems to have power of its own, in turn becoming a focal point for Traitor forces. And lastly, we have Olli shenanigans; the Perpetuals' mission draws closer to ending, and in doing so he finds deeper questions than originally thought.