Summer of 1868. Sherlock Holmes is fourteen years old. He is forced to spend his vacation at his relatives’ estate and is sure that ahead of him waits very boring summer holidays. But unexpectedly, two local residents die from a mysterious disease resembling the plague, and Sherlock finds himself at the very center of dangerous and puzzling events. Learning that the deaths of these people were the result of violence, the young Holmes begins an investigation and uncovers a devilish criminal scheme. Now he must face a dangerous and cunning villain who nurtures monstrous plans.