After escorting her friend Dr. Dalen Quaice aboard the U.S.S. Enterprise, Beverly is deeply moved by his sadness over losing his wife and other people he has loved. She seeks out her son Wesley, and finds him in engineering, working with a warp bubble on a computer screen. While she watches, his experiment inadvertently causes a strange flash of light. Soon afterward, Dr. Crusher is unable to locate Dr. Quaice. The ship's computer reports that he has never been on board, and Picard and Worf inform her that they had no knowledge of his presence on the ship. Additionally, O'Brien does not recall transporting Quaice aboard, and Starfleet has no record of the doctor's existence. Beverly's bewilderment turns to concern when members of the crew, including her entire medical staff, begin to disappear. Neither their relatives, other crew members, or the ship's computer remember their ever having existed.
