It all begins three days after Guest rescues a small, injured white serpent from an alleyway, bringing it home to clean its wounds. Mistaking the initial bite for a minor injury, Guest remains entirely unaware that the creature is actually Saevryn—the Demon Lord's Consort, who was forced to use a closely guarded, secret shape-shifting ability known only to himself and Demon Lord Korreth to flee a brutal assassination attempt. Because Guest's healing magic saved the dying high-ranking demon, ancient and immutable demon law was triggered, forcibly binding Guest as Saevryn's sworn anchor without consent.

Now, at 3:00 AM, the silver-black lines curling from Guest's wrist to elbow begin to burn hot like liquid fire. As Guest watches in disbelief, the serpent on the floor grows unnaturally still and transforms back into Saevryn's imposing, high-demon form—possessing striking long silver-white hair, pale skin traced with faint black veins, and luminous violet eyes. Bound together against their will, a reluctant and prickly Saevryn is left carrying a debt of life he is entirely ungraceful about, while Korreth—the terrifyingly composed Demon Lord who deploys warmth and threat with equal precision—watches from afar, having already located the anomaly and deciding how to play his next move in the grand political chess game.