In "The Bride Vanishes," a married couple must solve a mystery involving a disappearing bride and a haunted sea cave.
As the episode opens, a steamship is chugging along on its way to the island of Capri. Onboard are two Americans, Tom and Lucy Courtney. They are happy newlyweds who have come to spend a month in an oceanside villa.
Everything appears to be wonderful, but Lucy is worried about one thing. All of the other passengers stare at her and mutter. In fact, they seem to be frightened of her! Tom tells her that she is being silly, but soon they realize that the problem is real.
When they take a side-trip to visit the famous Blue Grotto, a boatman explains that Lucy looks just like a young bride who mysteriously disappeared on her wedding day. He also tells them that the villa they have rented is the same one where the strange disappearance occurred. He warns them that they must not stay there or Lucy may disappear too!
Will Tom and Lucy listen to the boatman? Or, will they unravel the mystery with the help of their friends...