Sherlock Holmes and his faithful sidekick, Dr. John Watson, have left on an extended holiday throughout Europe, leaving their nieces—Shirley Holmes and Jennie Watson—to keep an eye on the famous flat at 221B Baker Street. Shirley, studying logic, and Jennie, studying medicine, are busy preparing for upcoming exams when there's a knock on the door. It's Dr. Maxine Mortimer and Sir Henry Baskerville, who've come to seek the assistance of the famous Sherlock Holmes. Sir Charles Baskerville has died a mysterious death. Is he the most recent victim of the Curse of the Baskervilles—a curse linked to the nightmarish tales of a supernatural hound that haunts the murky moors of Devonshire? But wait, there's more! The young Sir Henry, the only surviving heir to the Baskerville legacy, has received a threat against his life! Something must be done! There's no time to recall Holmes and Watson from their trip. "We're all you've got," says Shirley. "We're up to the challenge," chimes Jennie. And indeed they are! In this fast-paced adaptation, full of wailing hounds, thundering hooves, and the slithering mists of the moor, Shirley and Jennie follow the trail of evidence and intrigue until, at last, they are confronted by the ravenous Hound itself!