The Enterprise decides to explore a unique black-hole nestled within a trinary star-system. As they are approaching at impulse, it will take a couple of days to get there, freeing the crew up for other activities. Since they have the time, Captain Archer asks Chief-Engineer Tucker to look at the Captain's chair on the bridge. Meanwhile, Ensign Sato volunteers to help in the galley for the ailing chef, and Lt. Reed begins works on some new ship wide security-protocols, and Dr. Phlox examines Ensign Mayweather about a headache. Archer also uses the chance to work on the preface on a book about his father.
Over the next few days, and with increasing compulsive focus, the crew starts obsessing on their selected tasks. Their behavior is also affecting their interactions with one another — Reed and Trip nearly get into a physical fight, while Phlox sedates a frustrated Mayweather so he can run more medical tests. The situation becomes so acute that Sub-commander T'Pol, who seems to not be affected, easily notices that the humans are behaving more oddly than normal; and, not just the humans, since she has to perform the Vulcan Nerve Pinch on Phlox who becomes intent on a biopsy of Mayweather's brain for further analysis.
T'Pol investigates further and discovers that a peculiar form of radiation emitted from the black-hole is the underlying reason for the crew’s increased irrationality. Unfortunately, in order to escape the radiation field, it will take another two days to reverse course. Fortunately, there is an alternate path where the ship can be safe within 17 minutes flying time, although it will require piloting the Enterprise closer to the dangerous black-hole. Unfortunately she cannot both navigate the treacherous field and pilot at the same time, now with the senior crew unconscious.
T'Pol rouses the groggy captain with a cold shower and hot coffee, enough that he is able to man the helm. His ability to fly is sluggish however, and as they near the exit, a large crumbling asteroid blocks Enterprise's path. Fortunately, Reed’s obsession created an automatic "Tactical Alert" that automatically kicks in and brings all defensive-systems fully online, thus, allowing T'Pol to blast the asteroids with the fully charged phase-cannon. Once outside the radiation, things onboard soon return to normal, with the exception of the captain's chair and Reed's newly proven security-protocol.