(NBC News) — On “Dateline” Friday, a mystery in paradise unfolds when Sarm Heslop, a British woman, vanishes from her boyfriend’s luxury yacht in the U.S. Virgin Islands.

“Dateline NBC” investigates the disappearance that made international headlines and left investigators with more questions than answers.

Here is a preview of Andrea Canning’s report:

Our story begins off the island of Saint John. Spring break 2021. Tourists were traveling again every hotel was sold out, every sailboat booked.

Anchored just a short distance from shore was a 47-foot luxury catamaran called “Siren Song.”

All was quiet on a warm, starry March night when suddenly an unusual distress call came from the boat.

Trevor Velinor: Our 911 dispatcher got a call at approximately 2:35 a.m.

The call was made by the boat’s captain, Ryan Bane.

He said his British girlfriend and first-mate, Sarm Heslop, was missing from the boat they’d been living and working on.

Ryan said his boat alarm had woken him up.

Trevor Velinor: There was a anchor alarm that alerted that the boat had shifted or moved.

Andrea Canning: Does Ryan have any idea where she could be or does he have a hunch or a theory or anything?

Trevor Velinor: He simply said, ‘Maybe she could have fallen off the boat?’

Watch “Dateline: Siren Song” Friday on NBC4 at 9 p.m.