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Elementary, Dear Data 

An attempt to provide Data with a challenging Sherlock Holmes holodeck RPG scenario backfires when its Prof. Moriarty character accidentally becomes self-aware.


Rob Bowman


Gene Roddenberry (created by), Brian Alan Lane

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Episode complete credited cast:
Patrick Stewart ... Capt. Jean-Luc Picard
Jonathan Frakes ... Cmdr. William Riker
LeVar Burton ... Lt. Geordi La Forge
Michael Dorn ... Lt. Worf
Marina Sirtis ... Counselor Deanna Troi
Brent Spiner ... Lt. Commander Data / Sherlock Holmes
Wil Wheaton ... Wesley Crusher (credit only)
Diana Muldaur ... Doctor Pulaski
Daniel Davis ... Professor James Moriarty
Alan Shearman ... Inspector Lestrade
Biff Manard Biff Manard ... Ruffian
Diz White Diz White ... Prostitute
Anne Ramsay ... Ensign Clancy (as Anne Elizabeth Ramsay)
Richard Merson Richard Merson ... Pie Man


When the Enterprise arrives a few days early at its rendezvous point to meet the USS Victory, the crew have a bit of leisure time on their hands. For Data and Geordi Laforge, it means a trip to the holodeck and 221B Baker St. With Data in the role of Holmes and Laforge as Dr. Watson, they take on a challenge from Dr. Pulaski that Data couldn't solve a genuine mystery. Data has a bit of time adjusting to a real mystery - as opposed to one for which he knows the outcome. In giving the holodeck computer its instructions however, Geordi's specifications for an opponent results in a far superior creation than expected putting them and the entire ship in danger. Written by garykmcd

Plot Summary | Add Synopsis




Official Sites:

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Release Date:

3 December 1988 (USA) See more »

Company Credits

Production Co:

Paramount Television See more »
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Technical Specs


Sound Mix:




Aspect Ratio:

1.33 : 1
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Did You Know?


Although this is the first time that Sherlock Holmes has been portrayed in Star Trek, there have been numerous cast members with a connection to the part. Leonard Nimoy played Sherlock on stage, Christopher Plummer played the part in Murder by Decree (1979), and director Nicholas Meyer wrote three Sherlock Holmes novels, one of which was adapted to screen in The Seven-Per-Cent Solution (1976). In that film, Sherlock's brother, Mycroft, was played by Jeremy Kemp, who plays Jean-Luc Picard's brother on this series. Benedict Cumberbatch from Star Trek: Into Darkness (2013) also plays Sherlock, while Star Trek veteran John Rhys-Davies has also played Doctor Watson. See more »


When Geordi tells Ensign Clancy he'll be gone for a while, Clancy asks where she can reach him. Data answers ironic "He can be reached at 221 B Baker Street". Although it sounds funny, this is not a professional response. See more »


Commander William T. Riker: [to Worf, who is dressed in a 19th-century suit] You'd be a big hit in London.
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Referenced in Trekkies 2 (2004) See more »


Star Trek: The Next Generation End Credits
Composed by Jerry Goldsmith and Alexander Courage
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User Reviews

One step closer to the TNG we know and love
1 May 2016 | by Mr-FusionSee all my reviews

'Elementary, Dear Data' may be a holodeck episode (and I honestly didn't expect all that much walking in), but it's one that refreshingly sees TNG up its game. This time around, it's Data and Geordi in a Sherlock Holmes mystery and Moriarty winds up taking over the ship. Not complicated, but I did like the big question being asked here: can a computer be alive? Dr. Pulaski spends a good deal of time haranguing Data for not being able to reason like real people (geez, this woman), while Moriarty yearns to learn more about the ship, stretch beyond his simulation limits and (more importantly) doesn't want his program being erased. But the situation is handled more thoughtfully than expected with Capt. Picard (in sweet top hat) brokering an understanding between the two.

All in all, a great episode; the wardrobe and sets are well done and you can tell Brent Spiner loves this Holmes stuff. More importantly, this actually feels like TNG: the characters feel right, Picard's actually softening, and everything's clicking.


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