A young girl newly arrived on the Enterprise whose imaginary friend was taken over by a curious alien life form.
Clara Sutter is the daughter of Ensign Daniel Sutter, who has recently transferred to the Enterprise. Having moved often, she finds it hard to make friends, so she invents an imaginary companion named Isabella.
In Imaginary Friend, an energy being from a nearby nebula takes on Isabella's form and becomes visible to Clara. Isabella leads Clara into trouble and grows hostile toward the adults who restrict her. Picard explains to the being why parents set limits for children, and the alien departs peacefully.