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



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Episode cast overview:
Lt. Commander Data / Sherlock Holmes
Wesley Crusher (credit only)
Biff Manard ...
Diz White ...
Ensign Clancy (as Anne Elizabeth Ramsay)
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

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Release Date:

3 December 1988 (USA)  »

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Aspect Ratio:

1.33 : 1
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Did You Know?


This is the only episode where Doctor Pulaski refers to Data as (Dayta) rather than her insistent later use of (Dahta). See more »


When Professor James Moriarty commands "arch", the arch can be seen in the back of the red chair and lamp. Shots later when data is moving away, the arch is somehow gone. See more »


Doctor Pulaski: It's elementary, dear Data.
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Referenced in Star Trek: Voyager: Alter Ego (1997) See more »


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

this is wonderful!
6 January 2008 | by (United States) – See all my reviews

A lot of the loose threads are left for other episodes. I'm not just referring to ship in a bottle, but also to measure of a man. Admittedly it bugged me when the Issue of Data's computer-like intelligence, which was the catalyst for the doctor's challenge and thus for the main problem, was not answered but one would need an entire episode at least to answer it and that is given to them about 6 episodes later.

For now Moriarty is a great villain and well performed by Daniel Davis. The entire episode has a metaphysical plot-hole the size of this continent but hey, Star Trek IS metaphysical! watch the above named episodes to get a sense of fulfillment to the issues raised. There are a few minor errors but this episode is amusing, intriguing, silly and classic all at once. Of how many episodes can that truly be said ? 4 or 5 stars.

13 of 16 people found this review helpful.  Was this review helpful to you?

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