Review of Mortis by John French

Titandeath, 53rd book in the Horus Heresy, was the BIG titan one. It's the one which properly put the massive war engines on the field of battle and turned them loose. Mortis (2021), fifth book in the Siege of Terra, turns what's left—horned or unhorned—toward the Emperor's Palace.

Mortis takes Horus' siege on Terra to the next level in bombastic fashion. World Eaters, Death Guard, Word Bearers, and Chaos continue their assault on the walls, and now, titans are unleashed from deep storage in the Emperor's palace to battle the Chaos titans Horus drops from space. The fields start to run slick, not only with blood, but also oil, prometheum, and all other manner of chemicals leaking from the damaged and destroyed siege engines. The war antes up.

But all is not blaster porn. French excellently captures several intimate scenes. A couple are reminiscent of the film Heat in which the two primary characters, the baddie and the goodie, sit down to have a civil chat. In the case of Mortis, this is the Emperor and Horus sitting under a tree in a dream-like desert, taunting and goading each other. The tension palpable, French gets a lot of subtle energy from these breaks in the battle.

Mortis also contains many scenes of a Horus Heresy character I do not have affection for: John Grammaticus. To be fair to Mortis, however, the book makes John matter, particularly a couple of the climactic scenes which peel back layers of critical perpetual lore and challenge John's mission to that point. Where much of the series is an Emperor vs. Horus-centric affair, these scenes attempt to ask: is there a third option for the conflict, which makes for some rumination—especially given the context is life and the continued existence of humanity.

If there is a challenge to Mortis, it is at the macro level: Loyalist forces continue winning battles yet the Traitors continue winning the war. Another way of putting this is, the majority of climactic scenes in Siege of Terra novels have featured the “good guys” winning. The “bad guys” somehow, however, keep gaining ground. I wish the series' architects had introduced a bit more anti-hero victories to underscore Horus' progress.

Before closing, a side note on Mortarion's presentation in the series as a whole, in short, it has been inconsistent. After multiple novels and stories, Mortis presents yet another version of the primarch. Perhaps this was inevitable given how he has been shared among the series' authors. Regardless, Mortis readers are given a new voice. The physical symbols that identify Mortarion are in place (sickle, breather mask, etc.), but his voice, mannerisms, etc. are again different than other books/stories. A shame that, but too late...

Mortis may be John French's finest effort in the Horus Heresy series. The prose is properly sharp, scenes are well defined, and the novel builds into a crescendo featuring a critical character's demise. The titans feel like titans, and their clashes have meaning to Horus' siege—something that was not 100% true in Titandeath. French seems to have taken the stakes of the final books in the series to whole heart, and produced a worthy volume in response. The book exceeded my expectations. And the Siege rolls onward!