Singularity

As the Enterprise nears a black hole in a trinary star system, radiation from the stellar phenomenon causes the crew to become increasingly erratic and obsessed with mundane tasks. Trip, for example, can't stop tinkering with the Captain's chair, while Phlox is fiercely determined to find the cause of Mayweather's headache. Eventually, crew members fall unconscious one by one, leaving T'Pol the only one left awake to save the ship.

Synopsis adapted from TVmaze (CC BY-SA 4.0)