For the Emperor (novel)

Commissar Ciaphas Cain and his aide Jurgen are transferred to the Valhallan 296th'301st, an Imperial Guard unit in transit aboard a spaceship, formed from the remnants of the Valhallan 296th and 301st Regiments after both sustained grievous losses. He is introduced to Colonel Kasteen and Major Broklaw, the highest-ranking officers from both regiments. Cain discovers that tensions between the members of the 296th'301st are rising rapidly due to clashing centuries-old traditions from both units. The tension comes to a head when a riot breaks out in a mess hall, with multiple casualties within the 296th'301st and the ship's crew.

With some luck and wit, Cain manages to defuse the situation, placating the angered ship crew and forging new unity between the Guardsmen of the Valhallan 597th, formed from the merger of the 296th and 301st. Members of the 597th responsible for the riot are sentenced to undertake suicide missions in the future.

Some time later, the 597th are assigned to the backwater planet of Gravalax as a show of force since the planet's locals have begun to defect to the Tau, a race of expansionist aliens. Tensions begin to rise between the 597th, the locals and the Tau. At a diplomatic event organised by Planetary Governor Grice, a Tau diplomat is assassinated. Nearly immediately after, conflict breaks out across the capital of the planet, with civilian rioters and traitorous Planetary Defence Force troops fighting against both Imperial and Tau forces. Cain and Lord General Zyvan are able to discover the presence of a conspiracy on Gravalax. During an operation to suppress the chaos, Cain encounters Ordo Xenos Inquisitor Amberly Vail and her retinue, who takes Cain and the convicted members of the 597th on a reconnaissance mission to the underground depths of Gravalax's capital city to uncover the conspiracy, where they join forces with a Tau unit.

Underground, they encounter numerous Genestealers, confirming Vail's suspicions of the conspiracy. During the mission, Kelp, one of the convicted Guardsmen, attempts to kill Cain, but is killed by Jurgen. Another, Trebek, is killed after being shot in the chest by Genestealer cultists. Two of the convicted, Holenbi and Velade, are separated from the rest in the underground tunnels. However, Jurgen is able to kill the leader of the Genestealer cultists, the Patriarch, throwing the remaining cultists into chaos, giving the group the chance to escape above-ground into Grice's palace. Grice shoots and kills Sorel, the last convicted Guardsman. Grice reveals himself as another Genestealer cultist, and engages the group in combat, where he reveals himself as the assassin that killed the Tau diplomat. Vail lands the killing blow, and the group is evacuated by the 597th.

After the battle, a dazed Holenbi and Velade are retrieved by a search team with little memory of their time separated from Cain, but Cain summarily executes them both with his sidearm. He uses a knife to remove a Genestealer implant in Holenbi's body, with Vail explaining to a sickened Kasteen and Sulla that both had been infected by Genestealers, and their disorientation and missing memory were sure signs of infection. Kasteen orders their bodies incinerated. Cain and Vail observe Tau soldiers exhibiting the symptoms of Genestealer infection being led away.

Soon after, the Tau mysteriously leave Gravalax behind, returning Gravalax to Imperial hands. Vail and Cain discuss the incident over a meal, where they discuss the extermination of the Genestealer cults; she also reveals Jurgen's nature as a psychic blank to Cain. The two toast to their friendship, and Vail promises to keep in touch with Cain.

Critical reception was generally positive.

On the website Goodreads, the novel has an average score 4.23 out of 5, aggregated from 2041 ratings at time of writing. Reviewers on the site compared Cain to the titular Harry Flashman and Edmund Blackadder of Flashman Papers and Blackadder series respectively.[1] The novel was also reviewed favourably on Amazon, with an average review score of 4.7 out of 5. Reviewers praised the novel's humourous, light-hearted nature and a good introduction to the universe of Warhammer 40,000.[2] Similarly, it is rated 4.7 out of 5 in accordance to 28 reviews on Apple Books at time of writing.[3]