Synopsis: Geordi plays John Watson to Data’s Holmes in a holodeck created mystery. However, since Data has memorized all of Doyle’s stories, he quickly solves the puzzle. When Pulaski claims that human understanding of mysteries and solving them is beyond Data’s ability, Geordi programs the computer to create an original story and invites Pulaski along to watch Data solve it. Unfortunately, the computer merely combines elements from different stories providing no more difficult challenge than the first attempt. Geordi instructs the computer to create an adversary capable of defeating Data and the computer obliges by creating a Professor Moriarty that is able to access the computer and even cause damage to the ship.