Legion of Super-Heroes #30 (1987) (High Grade)

Brainaic 5 takes a day to leave his laboratory and fraternize with his teammates. He apologizes to Sensor Girl for the way he reacted to her when he believed she was really Supergirl, and she forgives him, mostly. He then takes part of a successful mission and even goes to a night club with Sun Boy and Dawnstar. When Brainy finally arrives back at his laboratory, Computo informs him that Rond Vidar has passed away.