You don’t have much time to get to know your enemies in Warhammer 40K Darktide, because like other Left 4 Dead-inspired co-op games, the goal is to take them down as quickly as possible. But Darktide co-writer Dan Abnett, who is also the author of many popular 40K novels, says the sinister figures emerging from the shadows in Tertium’s underhive have a history, and a sad one.

There’s a new post from Abnett on the Darktide Steam page, and he explains the background behind some of the enemies we’ll be facing when the Warhammer 40K: Darktide release date rolls around in August. Many of them are chaos-tainted humans, including a regiment of some of the Empire’s finest troops, the Sixth Moebian.

Abnett explains that due to the game’s format, there is little time to get to know the individual personalities of the grizzled Moebian Sixth veterans. “You may not get to know them personally,” he writes, “but you will meet their types, and from that a picture of the Sixth Moebian will quickly build.”

According to Abnett, the soldiers of the Sixth are like recruits from anywhere in the Empire. They are commissioned at a young age and taken to the far reaches of space to battle alien and astral terrors they could never imagine in their time on Tertium. That is the threat that the citizens of the planet know as “the dark tide”.

That experience, he says, is frequently traumatic, if not completely fatal.

“Some soldiers, of course, serve brilliantly and bravely and stay loyal,” explains Abnett. “But others fall prey to the Dark Tide’s insidious touch. They meet the malevolent effect of the Warp, and it changes them. They literally become, in some cases, the very thing they are fighting against.”

The Moebian Sixth features a variety of troops, and you’ll encounter quite a few of them in Darktide: there are close-range melee fighters, flamethrowers, heavy weapons squads, and snipers. “They have everything you would need in an armed unit if you wanted to take down a world,” says Abnett.

Check out our hands-on impressions of Warhammer 40K Darktide from Summer Game Fest if you want to know more about how this sequel to Vermintide feels to play.