Julie, controlled by her fiancé, Kasim, is persuaded by him to visit her ancient Aunt Agatha at her isolated old manor house. Kalim plans to put an end to the aunt in the hopes that Julie will inherit her great wealth and raise him from debt. On arrival, he discovers the Folly, a building rumoured to house a great treasure, but considered inaccessible. Aunt Agatha, quickly recognising Kalim’s intentions, tricks the greedy gold-digger into visiting the Folly via the secret underground tunnel she has found. By candlelight, they pass into the tall structure and learn that Aunt Agatha is not as she seems as she locks them in. Darkness gathers, candles burn out and there, in the centre of the floor, evidence of a past murder lurks, threatening destruction and death.