Amethyst Rapture

In 1811, a curse was put upon a stone by a man who wanted his mistress to sleep only with him (and not with others as she often did).

After a shipwreck, the stone was lost in the waters off the coast of Port-au-Prince, Haiti. In current day, some divers off the coast of Cuba come upon it, and when it lands in modern-day Brandy's hands, she can't keep from throwing herself at Ryan, whom she otherwise would never be interested in.

But when the stone lands in dangerous hands, they have to release it back into the waters.