Complex sentence: The crew discovers his transport, and Wyatt's parents demand Picard bring Wyatt back to the "Enterprise", but Picard cannot, as Wyatt has since been infected with the Tarellian virus.
Split into simpler sentences: The crew discovers his transport, and Wyatt's parents demand Picard bring Wyatt back to the "Enterprise". Picard insists that he cannot return, as Wyatt has since been infected with the Tarellian virus.