Wrenn was a Tarellian and the leader aboard a Tarellian starship carrying the last known survivors of the Tarellian plague. His daughter was Ariana. Wrenn's group wished to settle on an isolated spot on Haven, a planet that was suppose to have healing powers. Haven's government officials refused Wrenn's request and the USS Enterprise-D was obligated to implement Haven's defensive response to any such attempt. However, Wrenn maintained the ship's course for Haven, considering it a last resort. His destruction, along with the rest of the survivors was halted at the last minute when Human physician Wyatt Miller made an unauthorized beam-over to their vessel from the Enterprise-D, determined and certain he could develop a cure for the survivors. Wrenn trusted Miller´s judgment and changed the