As Chakotay lies in sickbay, struggling to communicate with aliens with whom he is linked, he flashes back to the events that brought him there. He is in a boxing holodeck simulation when he is knocked out. Shortly after, Voyager is pulled into chaotic space, where the laws of physics are in flux. Shear forces may destroy the ship unless they redesign their sensors to work inside the disturbance. Suddenly, Chakotay begins hallucinating and hearing voices from the boxing ring calling to him. When he swings at Tuvok, he is subdued and taken to sickbay.
Voyager locates a ship adrift with no lifesigns aboard. Its last distress call reveals the captain began hallucinating just like Chakotay. The Doctor surmises Chakotay has a genetic marker for a cognitive disorder, and the dead captain had a similar experience when the protein insulation in his neural pathways was stripped. All of it is apparently caused by chaotic space, and Chakotay insists on taking a vision quest to learn more. Attached to a cortical monitor, he suddenly finds the aliens communicating through him. They tell him Voyager entered chaotic space through a trimetric fracture, and they must alter their warp field to escape.
When he can no longer hear the aliens, Chakotay re-enters his vision quest at the suggestion of the Doctor. He sees his grandfather, who suffered from the same auditory and visual hallucinations to which Chakotay is predisposed. Scared of becoming a crazy old man, he is continually pulled back to the holodeck boxing ring and an unseen opponent named Kid Chaos. Stuck in the vision quest, Chakotay is suddenly interrupted by the Doctor, who takes him back to sickbay.
In the Astrometrics Lab, Seven of Nine finds a pattern in the form of an isolinear frequency. Janeway realizes it is a nucleotide resonance frequency designed to activate DNA. She believes the aliens may be on a perceptual wavelength unknown to the crew, and their senses must be altered in order to communicate. Given this chance to make first contact, Janeway allows Chakotay to go back to the boxing ring, where he thinks the aliens are trying to tell him something.
Back in the ring against Kid Chaos, Chakotay begins piecing together the instructions he is receiving. His fear of losing control almost causes him to block out the voices, but the Doctor convinces him he must give in to it. Once the aliens tell him how to modify the deflector, Chakotay carries out the directions on the Bridge as the graviton shear quickly increases. Suddenly, Voyager's sensors set the correct course, and the ship is returned to normal space.