This might help:
Someone is going medieval on Marla's friends, brutally killing them one by one. When she tries to tell people what's happening - a cursed medieval knight is on a rampage - no one believes her.
The knight, whose captive, tortured spirit has been accidentally released in present day, is on a deadly quest. To release his soul, and the soul of the evil Queen Sofia who he onced pledged his loyalty, he must recapture his chivalric traits - Skill at Arms, Courage, Purity, Wisdom, Culture, Honor. Each of his victims represents one of these traits.
Marla possesses a family heirloom, the Amulet of Thorns. As a child, her mother explained to her in a fairy tale that this is a magical amulet and as long as she keeps it close, nothing can ever do her harm.
Once the knight reclaims his traits, he must get the amulet from Marla. In a final confrontation with Marla and her would-be hero boyfriend Jaxson, the knight has a change of heart and destroys himself, and the queen in the process.