John and Karen are at a casino, playing blackjack. Karen complains that going to a casino is not a typical lunch break, and that she's losing her rent money. John says that he's given her plenty of pointers. Karen scoffs at John's probability statistics, because she thinks that "gambling is all about luck." She then proceeds to hit on a fifteen, and ends up with twenty-five. Well, there's luck and then there's just stupidity. John quotes Boethius on the subject of chance, and Karen tells him to "Boe-ite [her]." Okay, that was kind of funny. John gets twenty-one, and then offers up advice to all of the other gamblers at the table, and they all win. He would have so gotten kicked out of the casino by now. The dealer busts, and everyone applauds John Doe. And then the dealer doesn't call the pit boss or security for some reason. John tries to get Karen to stay for one more hand by giving her some chips. Karen hits on a twelve, despite John's protestations. She gets twenty-one. John stands, and encourages everyone else at the table to do the same, so they do, each betting a whole stack of chips. Of course, the dealer gets twenty-one, and everyone but Karen loses. John sputters about "a statistical aberration." Okay, if he hadn't been kicked out by now, the other gamblers are surely going to kick his ass. Right? Wrong. Karen and John make a quick exit.
Two security guards walk through an art museum, discussing football. An alarm sounds alerting them to a security breach on the second level. A whole group of guards runs over the West Gallery and enters cautiously, guns drawn. One of them notes that "the ring is gone." None of the other artwork has been touched. But a female security guard, Cheryl Evans, is lying dead on the floor, victim of an apparent gunshot wound.
Frank surveys the crime scene, trying to get information from the museum's director about the victim. The director is more concerned about the missing Bishop's Ring than the dead security guard. Frank sets him straight. The director says that Cheryl worked for them for five or six years. Frank orders a cop to swab the exit in case the perp left fibers. The director says that didn't happen. Cut to the security guard HQ. The director explains that the gallery is magnetically sealed and bolted from the inside every night. The guards are locked in for four-hour shifts. Frank watches the tape of the shooting, taken from a security camera. On the screen, Cheryl drops to the ground, but a giant statue obstructs most of the view. Frank checks the other angles and wonders where the shooter is, and then asks if the main door is the only way in or out of the West Gallery. The security guard says that "a fruit fly couldn't get in without [them] knowing." Frank wonders why there isn't a camera trained on the Bishop's Ring. The guard says that there's supposed to be, and the director realizes that the camera has been moved off its axis. Frank says he's going to call a specialist, John Doe. The director asks who that is, and Frank replies, "Beats the hell out of me." No one talks like that. In the real world, the director would have been like, "Are you high? What in the hell are you talking about?" Then again, I'm asking for realism from this show, and I'm sure John could tell me that the probability of that happening is pretty low.
John and Frank stand in the West Gallery as Cheryl's corpse is wheeled out in a body bag. Frank runs down what they know: "A thief invisibly sneaks into a locked box. He kills a guard, evades three cameras, then pulls a vanishing act with a diamond ring as big as a kumquat." John babbles some facts about diamonds. A forensics guy calls Frank over and says that only the victim's prints were on the gun, so there must have been a struggle and the thief managed to turn Cheryl's gun back on her. John notices the details of the security system, and then says that the motion detector on the display case is miscalibrated. The director thinks that's impossible, so John has the detector armed and then gets Frank to move towards the case. No alarm sounds. He has Frank move towards one of the paintings, and the alarm goes off. John announces that by the time the alarm went off, the thief had the diamond in his hand. Aren't they making a lot of assumptions here about the gender of the thief? Frank asks sarcastically if the thief was both invisible, since he didn't show up on any cameras, and walked through the wall. John says he's just warming up.