||Whilst the Enterprise awaits a rendezvous with another starship, Geordi and Data decide to try out a new holodeck program based on the adventures of Sherlock Holmes. Data, having read all of the mysteries, instantly solves the riddle as soon as the program begins, much to Geordi's annoyance. As the pair discuss the problem in ten forward, Data is genuinely puzzled at his friend's reaction - as far as he is concerned, the whole point of the exercise was to solve the puzzle, and that's just what he did.
Pulaski, sitting nearby, interjects that the problem is that as a machine Data cannot do anything truly creative; he can only solve puzzles when he already knkows the answer. When Geordi objects, she proposes a bet - they will create a mystery based on the Holmes stories and see if Data can solve it.
They return to the holodeck - and again, data solves the puzzle instantly. Pulaski once again objects, this time because the computer merely assembled a mystery by compiling parts of different Holmes stories, all of which Data knows. Geordi asks the computer to create an entirely new mystery in the Holmsian style, featuring an opponent capable of defeating Data. The computer complies, and the three begin their investigation - unaware that a nearby hologram is watching them use the arch controls, aware of what they are doing.
This time there is a real mystery to solve - one which becomes more complex when Pulaski is kidnapped by Professor Moriarty, the earlier bystander. Moriarty is determined to know more about the mysterious arch he saw, and although Pulaski refuses his demands he is able to call up the arch himself and gradually begins to learn how to work the ship's computer. When Data finds his lair, Moriarti shocks him by showing him a drawing he has made of the Enterprise-D. Data and Geordi report to Picard, and Geordi realises that he inadvertantly asked the computer to provide an opponent capable of defeating Data, not Holmes.
With Moriarti gaining control over the ship's computer system, Picard goes to the holodeck personally to meet with Moriarti. The hologram insists he is self aware and sentient, and demands that he be allowed to live out some sort of life. Picard explains that it is impossible for Moriarti to leave the holodeck, which he reluctantly accepts. After Pulaski is freed Picard makes the Professor an offer - he will save the program, and Federation scientists will work on a method of letting him leave the holodeck. In this way, Moriarti might one day gain his freedom. Moriarti agrees, and the program is duly saved.
||A pretty good episode in most ways. By now we've become so used to the "holodeck gone mad" episodes that they are cliche, and you instinctively groan whenever it happens. But back here the idea was still relatively new, and it had a bit of mileage in it. That said, it still strains credibility that a holodeck can go bad in such a fundamental way. Or, alternatively, it strains credibility that the Federation would actually use the things if they were indeed this dangerous.
Beyond that, there are some nice touches. Pulaski's questioning of Data's status is interesting; the writers are clearly going for a McCoy/Spock vibe here, putting the two at odds and no doubt planning that they would eventually become mutual friends. The dynamics would be a little different here, since Data wouldn't provide any hostility back to Pulaski or respond to her barbs at all, but this could potentially have worked, I suppose. Only it never really did. Pulaski is the kind of "grumpy doctor" figure that McCoy was, but somehow it just never really works for her the way it did for McCoy. Nothing I can put my finger on, really, she just comes across as being a bit more arrogant, a bit less compassionate than McCoy was. And her jibes at Data just don't really work all that well. Perhaps because she's questioning his ability to solve problems in creative ways... but Data solves problems in creative ways every day. So Pulaski comes across as a bit of a fool to be questioning it. The thing about McCoy's jibes against Spock is that we all knew deep down that McCoy was right - Spock did have emotions, and they are valuable things. Pulaski is passionately arguing, but on the wrong side.
||Data claims that Holmes could only defeat Moriarti at the cost of his own life. Well I've read every Holmes story and novel written and this isn't true. I assume Data was referring to Holmes' apparent death on the Reidenbach falls, but in fact Holmes survived this and went on to live to a ripe old age.
This episode is one in a long running series that claim that holodeck matter cannot leave the grid. Yet Data walks off the holodeck holding a piece of paper that Moriarti gives him! And to recap, in "Angel One" Picard was hit by snow flying out of the holodeck, which them made a mess on the floor, and in "The Big Goodbye" Picard is kissed by a holographic woman, and walks out of the grid with her lipstick still on his face.