Charles and Grace wanted a quiet staycation honeymoon, but when their train terminates early due to a storm up ahead, they wonder if they made the wrong decision. Forced to take shelter in the nearest seaside town, Saltwater, they discover that there is only one guesthouse left. Unlike the rest of Saltwater, The Anchorage is entirely deserted.

That night, with the storm howling relentlessly, Grace is woken by a child crying. She is haunted by the sound, until Charles convinces her it was only her imagination. But the next day, she finds a warning scrawled in the guest book: Leave now. Do not trust them.

As the storm rages on, phone lines are down, transport links cut off. Grace is desperate to leave, but Charles remains unaffected by the eerie stillness of the house. Is it just Grace's imagination or do the owners, and Charles, have something to hide?