"Elementary, Dear Data" is the third episode of the second season of the American science fiction television series Star Trek: The Next Generation, the 29th episode overall. It was written by Brian Alan Lane and directed by Rob Bowman. It was originally released on December 5, 1988, in broadcast syndication.
Set in the 24th century, the series follows the adventures of the Starfleet crew of the Federation starship Enterprise-D. In this episode, a holographic adversary is created on the holodeck of the Enterprise when Data and Geordi take some time off to play a Sherlock Holmes game. The plot line from this episode was continued in the sixth season episode "Ship in a Bottle", and the Moriarty character appeared a third time in "The Bounty" (the sixth episode of Star Trek: Picard season 3).
In 1989, "Elementary, Dear Data" was nominated for two Emmy Awards: Outstanding Art Direction for a Series, Richard D. James, Art Director; Jim Mees, Set Decorator and Outstanding Costume Design for a Series, Durinda Wood, Costume Designer; William Ware Theiss, Starfleet Uniforms Creator.
Story and script
This episode contains elements from and references to the Sherlock Holmes short stories "A Scandal in Bohemia", "The Red-Headed League", "The Adventure of the Speckled Band", and "The Adventure of the Bruce-Partington Plans", as well as the Holmes novel The Valley of Fear. Furthermore, Moriarty's creation being a result of Geordi La Forge requesting an opponent capable of defeating Data references Arthur Conan Doyle's creation of the same character for the short story The Final Problem – specifically, as an opponent capable of defeating Sherlock Holmes who, at the time, Doyle wanted to kill off.
Reportedly, the original ending had Jean-Luc Picard lying to Moriarty, that he could have existed outside the holodeck, the same way the piece of paper on which he drew the Enterprise also stayed intact outside the holodeck. Co-executive producer Maurice Hurley wanted to keep that ending, as it made Picard look clever, but Gene Roddenberry nixed it, saying it made Picard look cruel. Instead, the paper stays intact without any explanation.
Casting
The episode features Daniel Davis as James Moriarty. Daniel Davis used an English accent for this role, though he is from Arkansas and speaks with an American accent when not in character. Davis was auditioning for the role of Moriarty alongside another actor in the room Brian Bedford directly in front of director Rob Bowman. Davis said of being in the room with Brian Bedford, "So he's the standout in my mind, and we were sort of taking bets with each other about which of us would get it. We hadn't worked together or seen each other in a long time. So it was a very friendly rivalry. Then, when I got it, he was a very good sport and invited me to come to dinner to celebrate that I had gotten the part." and the 26th best of all Star Trek episodes to date. James Hunt of Den of Geek gave it a 100% watch rating and remarked it was "fantastic episode". In particular he praised concepts explored about computers and artificial intelligence as well as the Data and Geordi character sequences. Keith DeCandido, writing for Reactor, rated it 7 out of 10.
In 2011, this episode was noted by Forbes as one that explores the implications of advanced technology, in this case for exploring an apparently self-aware software program.
In 2016, Time magazine rated the holographic Professor Moriarty as the 5th best villain of the Star Trek franchise.
In 2020, Looper listed this as one of the best episodes for Data, remarking that it is "The Next Generation having a whole lot of fun"; Geordi and Data tackle a holodeck gone wrong plot, with a Sherlock Holmes theme.