|This page contains spoilers for:||Ciaphas Cain (Novel Series)|
Kasteen was a company commander (most likely with the rank of captain) of the Valhallan 296th, an all-female rear echelon regiment, when it was deployed against the Tyranids on Corania. The regiment took over 50% losses and its command hierarchy was all but wiped out, leaving her as the senior surviving officer[1a][4a].
The 296th was merged with the all-male 301st, a planetary assault regiment, that had likewise been reduced to less than half-strength by the fighting on Corania. The differences between the two regiments were guaranteed to cause friction, and, to make matters worse, Kasteen was made the regimental colonel by virtue of three days' seniority over the 301st's surviving (and much more combat-experienced) senior officer, Ruput Broklaw, who was promoted to Major and became her executive officer[1a].
Tensions between the two former regiments - which continued to use their former regimental identities - came to a head on board the troopship Righteous Wrath on its way to the new regiment's first assignment to Gravalax in 931.M41, in a mess room brawl resulting in the deaths of several troopers and Naval provosts over the use of the 296th's regimental dinnerware to serve the meal[1a].
Realizing the situation, Commissar Ciaphas Cain - recently assigned to the 296th/301st - had the regiment renamed the 597th (296 + 301), and ordered the regiment integrated at squad level so that the number of male and female troopers was equally dispersed. Cain's efforts gradually restored the morale of the regiment, and Kasteen and Broklaw came to work together and respect each other[1b].
Kasteen led the regiment during the Gravalax Incident, intended primarily as a policing action to discourage the planet's Imperial population from defecting to the Tau Empire. The situation quickly became dangerous when the Tau ambassador was assassinated at a reception being hosted by the Governor. Kasteen happened to be attending the reception with Cain, and the two of them managed to establish a rapport with the Tau commander, that allowed them to prevent open war from erupting between the two factions[1c][1d].
Kasteen also skillfully coordinated the regiment in suppressing the minor rebellion that broke out on the planet, which escalated into open battle when the insurgents were revealed to be under the influence of genestealers[1e][1f]. The 597th's first campaign was generally hailed as a success.
About a year after the Gravalax Incident, the 597th was deployed to Simia Orichalcae, to defend a vital promethium refinery from an Ork invasion. Like all Valhallans, Kasteen was both well-trained and eager to combat Orks, and Cain approved of all her tactical decisions[2a].
When the refinery administration insisted on being kept in the loop, Kasteen (with Cain's backing) declared martial law on the planet when it became clear that the Administratum was unprepared to defend the facility[2b]. She later ordered the planet's evacuation with the discovery of Necron activity beneath the facility, and coordinated a fighting retreat from the Orks, allowing the regiment to escape the planet with minimal casualties[2d].
About two years after the Gravalax Incident, the 597th was deployed to Periremunda. As with Gravalax, the planet was undergoing civil unrest, which was presaging the arrival of a Tyranid Hive Fleet. Although Kasteen admitted to feeling a trace of fear at facing the Tyranids again - since they had chewed their comrades to pieces on Corania - she acted with her usual level-headedness, and effectively coordinated the defense of the planet's plateaux from the incoming swarms[4a].
Early on in the campaign, Inquisitor Amberley Vail, who had foreknowledge of the Tyranids' approach, allowed Cain to share this knowledge with Kasteen and Broklaw, deciding that they were trustworthy[4a].
One of the 597th's most difficult trials came approximately five years after the Gravalax Incident, when the 597th was deployed to Adumbria, which was expecting an invasion by a Chaos warband known as the Ravagers[3a].
During the initial journey, tensions ran high between the 597th and the 229th regiment of the Tallarn Desert Raiders who were being deployed along with them. The Tallarns had a conservative disdain for Guard regiments that included women in their ranks, and their regimental commissar, Tomas Beije, was unable to hide his open astonishment that the 597th had a woman as its commanding officer[3a].
While the 597th was being deployed on the planet's night side, several minor skirmishes with Chaos Cultists suggested that the situation was more complex than the Imperial forces believed. After the Ravagers made their first attacks on the planet, Kasteen noticed a pattern which eluded most of the other command staff, which revealed that the Ravagers had come to stop a Slaaneshi cult that was conducting rituals to summon a Daemon. Based on her observations, Cain was able to deduce the site of the last ritual, and diverted a Troop transport to the site[3b][3c][3d].
Beije, a long-time rival of Cain's, believed that Cain was a coward looking for any excuse to avoid the frontlines, and followed with the intent of arresting him. Beije's ill-considered remark that Cain had seized on his "petticoat Colonel['s]... ridiculous theory" enraged the Valhallan troopers accompanying Cain, and prompted the Commissar to challenge Beije to a duel if he did not apologize to Kasteen[3e].
Kasteen's "ridiculous theory" was, in fact, entirely correct, and Cain's impulsive actions succeeded in interrupting the cultists' summoning ritual, which would have resulted in transforming Adumbria into a Daemon World. Afterwards, Kasteen was warmed by Cain's defense of her and she and Broklaw stood by him when he faced the tribunal that Beije insisted on convening. The tribunal decided in Cain's favor, and Beije, having seen Cain's skills with a chainsword and laspistol firsthand, humbly apologized to Kasteen rather than duel him[3f].
When the 296th and 301st were consolidated, Kasteen was protective of her former comrades of the 296th, and was hostile towards her counterparts in the 301st. Once the regiment was fully combined and the changes Cain had introduced took hold, Kasteen took to her position as commander of the mixed-gender 597th[1b].
Before the Governor's reception on Gravalax, she admitted to feeling her youth and relative inexperience, but Cain shored up her self-confidence by assuring her that her promotion was entirely deserved[1c].
In his private memoirs, Cain reflected that, although it was simple luck that had elevated her to command (by virtue of being the only senior officer left after Corania), it was the best fortune for the regiment that she proved to be such a gifted leader[4b].
Like most Imperial Guard officers, Kasteen had very little patience for the bureaucratic pandering of the Administratum (Cain later wrote in the Cain Archive that Kasteen had an even lower tolerance for idiots than he did), and adopted a soldier's blunt approach to problem-solving that suited her well. By the time of the Simia Orichalcae deployment, she was fully confident of her own authority, and declared martial law rather than engage the Administratum deputies in pointless debate about her decisions[2b].
For instance, when she proposed mining the route by which an Ork Gargant was approaching the facility, the refinery administrator warned about the dangers of damaging the refinery and demanded an alternative strategy. Kasteen's curt response was that the administrator was welcome to "ask the Orks to go away if she thought that would help."[2c]
Cain became close friends with both Kasteen and Broklaw - a remarkable achievement for a Commissar, and this friendship often made him think of himself as one of the regiment, rather than an outsider. Some outside the regiment speculated whether there was ever any romantic attachment between the two; in his memoirs, Cain quashed the rumour, but expressed some regret about the fact, given that Kasteen was both attractive and of strong character[1c].
- 1: For the Emperor (Novel) by Sandy Mitchell
- 2: Caves of Ice (Novel) by Sandy Mitchell
- 3: The Traitor's Hand (Novel) by Sandy Mitchell
- 4: Duty Calls (Novel) by Sandy Mitchell