Thomas Alden was a Federation Starfleet scientist and physician, of apparently British descent, on active duty in the early 25th century. Alden had at least one sibling, Caroline. He also had a difficult relationship with his father, also a physician in private practice on Earth. (Star Trek: Phoenix: Dr. Thomas Alden character vignette) Prior to Alden's being recruited as USS Phoenix's chief medical officer, he was an exobiologist stationed at Starbase 515. He was an old friend of Captain Bryce Avari and the two had not seen each other in eight years. (Star Trek: Phoenix: "Cloak and Dagger")