On a remote island in the Scottish Hebrides sits a castle of gleaming red sandstone. By day, it is the picture of elegance. But when night falls, its secrets are revealed ...

A showgirl named Emerald, rising star of London's Gaiety Theatre, is invited to spend a country house weekend on this remote Scottish island by Lord Lyndon Gunn, a mysterious and wealthy Scottish bachelor. There she is dazzled by her lavish surroundings - gilt-panelled ballrooms, hothouses filled with hummingbirds and orchids, and meals featuring delicacies including French ortolan and quail, along with the finest Champagnes.

But it is not long before Emerald - who has secrets of her own - realises things are not quite as they seem. Why are the servants blindfolded when the sun goes down? Who is the mysterious older American woman who behaves like the lady of the castle? And are the rumours of a hushed-up scandal - that someone disappeared at the last party - true?