When childhood friend, Lyssa, asks the Charmed Ones to be bridesmaids at her seaside wedding in Serenity Cove, there is much excitement. But the course of true love never does run smooth. The ceremony is set to take place in the beautiful old lighthouse, which is believed to be haunted by the vengeful spirit of a lighthouse keeper who lost his true love at sea a hundred years ago, on the same day as Lyssa's intended nuptials. The rumors are dismissed, until Lyssa's fiance begins to act strange and overly interested in the family heirloom, a rare mystical diamond called The Light of the World. The Halliwell sisters must disclose the groom-to-be's true intentions, and identity before their friend says 'I do' to Mr Wrong.