Swordheart by T. Kingfisher — book slip

Halla, a housekeeper, unexpectedly inherits her great-uncle's estate, only to face scheming relatives intent on seizing her newfound wealth.

Seeking solace, she unsheathes an ancient sword, releasing Sarkis, an immortal warrior bound to protect the sword's wielder.

Together, they navigate threats from bandits, inquisitors, and Halla's own family, all while confronting the enigmatic dangers posed by the sword itself.

For fans of The Princess Bride and From Blood and Ash.