Sue is an entity that seems linked to the latest changes on The Run Around Sue. She came from the planet that she calls Hell, and now claims that she has always been a member of the crew of the ship. She believes herself to be involved in a love affair with Captain McIntyre, and refuses to listen to the contrary.
While Sue appears to be human, she has exhibited strength well beyond human norms, and has displayed a level of knowledge and intelligence that seems unnatural as well. She apparently speaks and understands The Observers language, and when exposed to a Church communication, apparently learned Latin in a just a few minutes of time.