Mysterious and terrible things happen in a house near the forest, where a respectable couple, the Bensons, lives peacefully. Ominous sounds disturb them at night, books fall from the shelf on their own, and a mysterious figure in white wanders through the garden... A ghost? The tricks of the “dark forces” are becoming more and more dangerous: the garden is destroyed, the pond is poisoned, and the barn is on fire. Who scares old people and why? Members of the Detective Club - Holly, Tracy and Belinda - decide to protect them and bring the criminals to light...