The leader of the handful of Tarellian plague survivors who bring their ship to Haven in the hope of finding an isolated place to live out their days.
Wrenn commands the last known Tarellian vessel in the first-season episode Haven. His people destroyed themselves in a war fought with a biological weapon, and the few who escaped were hunted down by neighbouring worlds terrified of infection.
He tells Picard that only eight of them remain. They have not come to Haven to harm anyone, but to settle on a deserted island and die in peace on a world of legendary beauty. He accepts that the Enterprise cannot let them land.
Among his crew is Ariana, the woman the human physician Wyatt Miller has seen in his dreams since childhood. When Wyatt beams aboard with medical supplies to search for a cure, Wrenn welcomes him and takes the ship away from Haven.