A disturbing incident from T'Pol's past prompts her to seek Archer's help in apprehending a renegade undercover Vulcan agent wanted for smuggling biotoxins used to make weapons.

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.