Dr. Watson returns from a staff night out with The Strand magazine to find Sherlock Holmes manufacturing a new hallucinogenic narcotic with his chemistry set. When professional nanny Miss Violet Hunter consults the great detective about a job offer in Winchester, Sherlock Holmes believes that the standard of clientele has hit rock bottom. Nevertheless, he finds her extremely attractive, and when she asks for his help in her new position, he answers her call enthusiastically. After an intoxicating lunch in Winchester, Holmes and Watson supplement their wine intake with ‘chimps’ – the tablet form of the new narcotic – so when they reach the home of Miss Hunter’s employer, they are flying. They perceive an avenue of copper beeches to be a kaleidoscope of psychedelic trees; experience a myriad of mind-boggling spectacles; uncover an intimate secret about their client and use the Manstopper revolver without the respect it deserves.