One of Batman’s key allies, Batwoman, has just gone rogue - and even killed one of the Dark Knight’s allies.

When James Tynion IV took over DC’s Detective Comics as part of the DC Universe’s “Rebirth,” he launched the series in a whole new direction. Tynion had the Dark Knight assemble a group of potential heroes, attempting to forge them into a team who could protect Gotham. In order to train them, Batman teamed up with Katherine “Kate” Kain. Daughter of rogue military leader Jacob Kane, this so-called Batwoman is a military figure. At times, that’s led to conflict between Batman and Batwoman; now, though, the rift seems to have become impossible to gulf. Batwoman has just killed one of Batman’s allies.

Batwoman’s victim is Clayface, a classic Batman villain. Batman had learned that Clayface’s insanity was a byproduct of his powers, and had dedicated all his resources to curing him. These attempts had mostly proven successful - until a group of villains known as the Victim Syndicate intervened. They drove Clayface insane once more, and amplified his powers to a terrifying scale. While Batman struggled to find a way to save Clayface, Batwoman went to her father, and acquired a weapon that could kill Clayface once and for all. When the moment came, she took the shot.

Detective Comics #974 sees Batman and his allies reeling from Batwoman’s shocking decision. Worst of all, so far as Batman is concerned, is the fact she doesn’t seem to realize she did anything wrong. To Batwoman, the threat level was too severe, and Batman had already failed to contain it. So far as Batwoman is concerned, the kill-shot was the only option.

That idea runs counter to everything Batman stands for. He’s training his young wards not to kill, under any circumstances. Heartbreakingly, that “no-kill” rule becomes the dividing point for Batman’s team. Some can understand Batwoman’s position; others wholeheartedly reject it. Orphan tears the bat-signal from Batwoman’s chest, telling her that this symbol is supposed to mean something. “Means don’t kill,” she snarls. “Means never kill.”

Rejected by the Batman, Kate Kane goes to the only one who will accept her; her own father, a man who launched insane attacks on Gotham City himself. Jacob Kane believes that the darkness in Gotham can only be contained through the shedding of blood, and now he has an ally in Batwoman. Meanwhile, Tim Drake is furious. He recently glimpsed a future timeline in which Kate destroyed everything Batman had tried to build, but believed it wouldn’t come to pass. Now he believes he’s been proved wrong, and there are hints Tim is launching his own vendetta against Batwoman.

The Dark Knight’s alliance is falling apart, all because of a single shot from a sniper rifle. Batwoman has gone rogue, committing herself to a life that will bring her into direct conflict with Batman. And Batman’s smartest Robin is dangerously broken.

These are dark days for the Dark Knight.

MORE: 15 Times Batman Has Killed People

Detective Comics #974 is in stores now from DC Comics.