DC Comics has remained tight-lipped about Tom King’s upcoming seven-issue limited series Heroes in Crisis, revealing officially only that the story would focus on a murder mystery at the Sanctuary hospital. Now, though, an extended synopsis and fact sheet has emerged, allegedly revealing additional details about the event and the roles of two characters at its center — Booster Gold and Harley Quinn.

The documents began circulating online on Thursday, when they were obtained by Newsarama. The pages themselves appear to be from the next edition of DC Previews. If real, they confirm that Heroes in Crisis will be centered around a mass murder at Sanctuary, a place where superheroes go to recuperate from post-traumatic stress brought on by the violence that defines their jobs, and that Booster Gold and Harley Quinn will be the prime suspects.

RELATED: What DC’s Heroes In Crisis Cover Tells Us About King & Mann’s New Series

“There’s a new kind of crisis facing the heroes of the DC Universe, ripped from the real world headlines by C.I.A.-operative-turned-comics-writer Tom King: How does a superhero handle PTSD?” The synopsis reads. “Welcome to Sanctuary, an ultra-secret hospital for superheroes who’ve been traumatized by crime-fighting and cosmic combat. But something goes inexplicably wrong when many patients wind up dead, with two well-known operators as the prime suspects: Harley Quinn and Booster Gold! It’s up to the DC Trinity of Superman, Wonder Woman and Batman to investigate — but can they get the job done in the face of overwhelming opposition?”

The attached fact sheet reveals additional details about Sanctuary, like how the hospital was built five years ago by Batman, Wonder Woman and Superman after the trio realized that the new generation of superheroes would need help coping with the violence they see daily. Sanctuary itself looks like a small, rustic Nebraska ranch to the outside observer, but is actually a state-of-the-art facility built using Kryptonian technology.

RELATED: First Page from DC’s Heroes in Crisis Spotlights Harley Quinn, Booster Gold

There are also some smaller details, like the fact that Sanctuary is manned only by holograms and robots, but that the facility offers extensive therapy treatments for its patients. Also, the existence of Sanctuary is a secret. No one from the outside world knows about Sanctuary, which begs the question: How did the villain who attacked the facility know about it in the first place?

Among the three founders, Batman considers Sanctuary a “necessity,” while Wonder Woman considers it a “kindness” and Superman thinks it is an example of doing “good.” Lastly, and perhaps most importantly, is that, when the event kicks off, everyone in Sanctuary will be dead.

Heroes in Crisis #1 by Tom King and Clay Mann hits comic book store shelves on Sept. 26.