The discovery of a strange Shuttle malfunction in the medical bay causes the ship to be corrupted by an alien virus. Obrien, investigating the Shuttle malfunction, is evolved into a being of pure energy and drawn into a strange world, where nothing makes sense. Meanwhile, romulan ships are converging on the enterprise, and Obrien must make contact with the unknown aliens causing the Shuttle malfunction before time runs out. fortunately, with the help of Barclay Calibrating the gravitic dynoscanner with forward subspace inhibitors and an old log entry by bajoran, Obrien is able to establish peaceful relations, saving the day. As thanks, Obrien is un-evolved into a being of pure energy, and tells a funny anecdote about the experience.