Henry Semel is a doctor on an unnamed planet caught in a slipstream eddy. The Andromeda's crew traveled to the pre-contact planet to look for a crashed Slipscout which held a complete map of Slipstream in its datacore. Dr. Semel and Tori Leighton found Dylan and Beka wandering through the forest. They were pretending to be adventure tourists from North Sodzee, a nation on the planet. Beka pretended to be injured, and Dr. Semel, who is apparently familiar with basic anatomy, treats her supposed leg injury. Dylan and Beka are invited back to the conservatory that the others are both stationed at so that Beka can get some water and medicine. He and Beka get romantically involved, until Beka and Dylan have to run away when Amory Sutton at the conservatory finds out that they are aliens. ("Deep Midnight's Voice")
He is played by actor Cameron Park.