Halla has unexpectedly inherited the estate of the wealthy distant uncle she's been caring for for the past decade. Unfortunately, she is also saddled with money-hungry relatives full of devious plans for how to wrest the inheritance away from her.

While hiding in her bedroom to escape her family, Halla inspects the ancient sword that's been collecting dust on the wall since before she moved in. On a whim, she pulls it down and unsheaths it—and suddenly a man appears in her bedroom. His name is Sarkis, he tells her, and he is an immortal warrior trapped in a prison of enchanted steel.

Sarkis is sworn to protect whoever wields the sword, and for Halla—a most unusual wielder—he finds himself not fending off grand armies and deadly assassins but instead everything from kindly-seeming bandits to roving inquisitors to her own in-laws. But as Halla and Sarkis become closer, they overlook the biggest threat of all—the sword itself.