Elementary Dear Data

Star Trek: The Next Generation  Season 2 Episode 3

Air Date: 12/5/1988

Stardate 42286.3 While en route to rendezvous with the USS Victory, and with a bit of time to kill, Data and Geordi enter the holodeck. Slipping into their respective guises of Sherlock Holmes and Doctor John Watson, the two begin one of the adventures of the Sherlock Holmes novels. However, since Data knows all of Sir Arthur Conan Doyle's works on Sherlock Holmes, Geordi has the holodeck computer create a new challenge for Data, and not Sherlock Holmes. This leads to a holodeck creation that threatens the entire ship. Can their new holodeck Moriarty be defeated?