Chaotic space was an extremely energetic zone where the laws of physics were in a state of flux, causing an extreme hazard to navigation. Chaotic space would appear randomly and at unexpected locations, making it extremely unpredictable. Forces encountered inside the phenomenon included subspace flux, graviton waves and spatial sinkholes. The Borg had observed the phenomenon of chaotic space throughout the galaxy, although only one cube ever survived an encounter as of 2375.
In that year, the USS Voyager inadvertently entered a region of chaotic space in the Delta Quadrant through a trimetric fracture, subsequently becoming trapped. This zone was two light years across and emitted enough energy for a dozen stars. Initial attempts to navigate out of the zone met with failure, as the graviton shear threatened to breach the hull. The crew attempted to drop a series of beacons to help them navigate, but discovered that, while apparently traveling in a straight line, they had actually been navigating in a circle, which brought them back to the location where they had dropped the initial beacon.
As the crew was attempting to locate a means by which they could escape the phenomenon, Commander Chakotay began experiencing a series of hallucinations, a result of the reactivation of a gene responsible for sensory tremens, a disorder from which his grandfather had suffered. It was eventually discovered that the reactivation of the gene had been initiated via an isolinear frequency, by a race of aliens indigenous to chaotic space, who were attempting to assist the Voyager crew in escaping. The aliens existed on a perceptual wavelength that normal humanoid senses could not detect. Though Chakotay did not completely understand the geometry involved, he managed to learn that chaotic space intersected the normal spacetime continuum at the eighteenth dimensional gradient, and that, by recalibrating Voyager's deflector dish, he could modify the ships warp field to a paralateral rentrillic trajectory with which to escape. Routing the deflector through the sensor array, and activating the dish to maximum amplitude, Chakotay managed to find Voyager a route out of chaotic space. (VOY: "The Fight")