“If a door is closed, you leave it alone.”

That’s the one rule janitor Sam is given when he starts cleaning the infamous thirteenth floor of the Denver branch of Hell-like multinational corporation Dark Enterprises.

Sam is thrilled to be that much closer to his idol, Constantine Galanos, Denver’s ruthless and charming CEO, but he’s even more excited to uncover the tantalizing secrets lurking up on the executive level. Maybe he’ll find something juicier than tawdry workplace affairs and petty office gossip, something he can share with his closest friends, daredevil Mia and secret crush Calvin.

When Sam comes across a closed door his first day on the job, he thinks one little peek can’t hurt. But he’s dead wrong. Behind that door is a Type A biohazard—infernal materials from Hell on company property—and a deal that could spell doom for Dark Enterprises and Earth…signed by the CEO himself.

Sam is in deep trouble now, and the problems keep piling up. The CEO’s homicidal assistant wants him fired (read: killed), Calvin is literally losing his mind over a secret project, and there’s something very unusual about Mia’s emotional-support rabbit, Mr. Bun-Bun…

It’s a mess like no other, but Sam is a janitor at Dark Enterprises. If he can’t save humanity as well as the man of his dreams, no one can.