Federal investigator Avery, looking into her mother's disappearance, receives a wedding group photo of an "unevent" and sneaks alone into Vale Manor. In the underground treasure vault, she discovers that the groom Sebastian is a vampire who has lived for 109 years, sustaining his eternal youth by harvesting brides' lifespans through weddings. That very night, she is forced to sign a blood contract marriage certificate, say "I do", and put on an emerald ring that bites into her flesh, becoming his fourth bride; if she cannot remove the ring before dawn, the marriage will be sealed for life. The ghosts of the three deceased wives secretly assist her, and she finds that the old signature on the marriage certificate bears the unique handwriting style of her mother — Avery must team up with the ghost brides to turn the tables on this century-old hunt under the guise of love before her own lifespan is drained away.
