The episode begins with Riker and Geordi on the surface of an alien planet. Riker has just been spiked in the leg by something, and they’re worried the wound might be full of alien crawlies. Although he laughs it off, the transporter is unable to filter out a possible infection, so Pulaski beams down to inspect his injury.

Declaring Riker’s leg medically unfit for duty, Pulaski insists he beam back to the ship. They discover that Riker has indeed been infected by something not quite a bacteria, not quite a virus, but very difficult to get rid of. Worse, it’s already given him a dead leg, and now it’s spreading up his body towards his precious brain, which is the place where he keeps all of his memories and knowledge of various lovemaking techniques.

Although he seems in good spirits, cracking jokes with those visiting and attending to him, Troi comes to visit and can sense his fear. Riker remains resolute, saying that if he has to die, let it be with his sense of humour intact. The universe obliges, and he promptly passes out as the Bacterio-viral-infection spreads to his spinal column (that’s the main thing that keeps you conscious, if I remember my human biology correctly).

Desperate to save Riker’s life, Troi and Pulaski insist on undressing him during an advert break, place a shiny medical blanket atop his bearded form and then drive a series of needles into his brain, forcing it to stay active as the infection spreads to it.

For the remaining thirty minutes, we are treated to scenes of Riker remembering the events of previous episodes. That’s right, it’s a clip show. A “Best of Riker” clip show. Intercut with these “memories” are brief scenes of Troi and Pulaski monitoring the effect that electrocuting various sections of Riker’s brain has on the spread of the infection as they try to get it under control.