No, really, thats the plot of this episode.
OK, to put it the way the show puts it, Riker is rendered unconscious by the infection, so Pulaski and Counselor Troi put him into a machine that stimulates the memory centers of his brain, which seems to help. The problem is, not only does this mean this episodes a clip show, its a clip show made up entirely of clips of Riker, and just from the first two seasons, mind you. So most of the episode is a lackluster selection of recycled footage intermixed with scenes of Pulaski and Troi staring at an unconscious Riker. Even by clip show standards, this ones pretty weak.
In the end, Pulaski finds a group of memories that fight off the infection: the memories of the times he got his ass kicked or nearly blown up. Soon Riker is ship-shape again and so season two ends, on kind of a sour note for a season that was otherwise a pretty big improvement over season one.
This episode is often seen as an example of how today's audiences have greater expectations of series of this nature. Today, while it is not uncommon for arc-heavy shows to air standalone "recap specials", and clip episodes occasionally rear their heads as mid-season filler, it is unheard of today for a season finale of a show of the stature of TNG to be blown off as a clip show. It only exists because of the writer's strike that year, as the crew had already blown through all the previously existing scripts from the aborted "Phase II" series, and because of budget overruns on the episodes "Elementary, Dear Data" and "Q Who", forcing the crew to save money at the end of the season.
Tropes in this episode:
- Bottle Episode: This was intended to be a high-quality, low-budget episode, using only three sets and not even showing the bridge, but it mostly comes off as a cheap letdown of a season finale.
- Clip Show: The only example of such in the entire Star Trek franchise. It was so appallingly received that whenever Paramount tried to pressure the show's producers into making another one to save some money, they were able to quickly shut the discussion down by pointing to this episode as proof of why it was a bad idea.
- Identity Amnesia: Played with—Pulaski notes there may be some memory loss, and asks Riker who he is as Picard and Data walk in. Riker smirks and says he knows perfectly well who he is—he's Captain Jean-Luc Picard of the U.S.S. Enterprise.
- The Main Characters Do Everything: Why are the first officer and chief engineer surveying the planet instead of a science team?