As Troi gets ready for bed, however, she has a memory flashback: poker chips falling, Will asking her "have you stopped thinking about us?", and her attempts to fend off some advances. Suddenly, the scene turns violent-and Riker changes into Jev. Vision-Troi screams-and the real Troi slumps to the floor in a coma.
The next morning, Bev's still unable to bring her out of it, and has no clue what might have caused it. Thinking that perhaps the Ullians might have unintentionally carried something harmful on board, Riker goes to discuss the matter with Jev. He's rather blunt about his suspicions, however, and brusquely leaves once Jev fully agrees that all three of them will cooperate. That night, Riker talks to Deanna and tells her to wake up soon; Beverly orders him to bed.
Then, as Riker's in his quarters, he has a flashback: An emergency of some sort in Engineering, involving an isolation door coming down and trapping an ensign on the other side. Suddenly, the ensign accusing Riker of "you killed her!" turns into Jev, and starts appearing in various locations. Vision-Riker looks around, frantic; and the real Riker slumps to his bureau in another coma.
The next day, Beverly's ruled out any known medical cause [the only illness that leaves traces similar to what she's found also has other side effects which have not appeared]. She puts Geordi to work searching for other possible causes of the electropathic activity she's found- and since the activity was located in the thalmus [the memory center], she suggests Picard once again question the Ullians.
Tarmin is indignant, but all three again offer their full cooperation in the matter. Beverly scans Keiko, who had a memory retrieved by Tarmin days earlier, and finds no trace of any abnormal activity. As Geordi's search also turns up empty, Bev searches for other causes-and then she has a flashback. It's nearly twenty years earlier; she and Jean-Luc are on their way to see Jack Crusher's body. Jev slips in and out of Picard's position as they approach the body- and as the coverlet is removed, Beverly sees Jev/ Jack open his eyes and stare back at her. Vision- Beverly screams: and by the time Geordi and Data report to her, she's slumped at her desk in yet another coma.
Picard orders Geordi and Data to search the records of the previous planets visited by the Ullians during this mission, and then asks the Ullians to voluntarily confine themselves to quarters temporarily. Jev suggests probing the now-revived Deanna [she remembers being scared and upset, but not what frightened her] to prove their innocence. Tarmin refuses to have anything to do with it, and Picard demurs, but Inad convinces him that they deserve that much of a chance. As Geordi and Data find correlations between comas on some of the planets and the Ullians' visits to them, Jev probes Troi, who relives the events of three nights previous- except that this time, the invader of her memories is not Jev, but Tarmin.
Tarmin is monitored by both Jev and Inad, and Jev apologizes to Picard for his conduct, saying that what he has done is a grave crime in their society. (Tarmin is claiming innocence.) Data and Geordi, meanwhile, find from the last two planets' information that Tarmin was not on one of those worlds when several unexplained comas broke out. Jev goes to say goodbye to Deanna, but her kindness towards him causes him to lose control. He again invades her mind, this time coupling it with a physical assault-but Data and Worf show up in time to stop him. Tarmin, deeply grieved by his son's actions, tells the three victims [all now awake] that Ullia's best physicians will help them back on the road to full recovery.