 They discover that an unknown source of Eichner radiation is causing the growth. Separately, Ian (R.J. Williams), now appearing as an eight-year-old, confides to Troi that he is the source of the crew's problems and will have to leave. Troi realizes Ian is dying and calls for medical assistance. As Pulaski tries to keep Ian alive, Lt. Commander Data (Brent Spiner) scans him and discovers that he is the source of radiation. Ian dies in Troi's arms, and turns into a ball of energy, which settles into Troi's hands, communicating telepathically with her for a moment, then leaves the ship. The lifeform told her that he wished to experience childhood and living among the crew. With Ian gone, the plague sample returns to normal and the crew continues on to Starfleet Medical.
