Lieutenant Reg Rosemont was a geologist and land surveyor on Captain Cordelia Naismith's Betan Astronomical Survey vessel Rene Magritte. While exploring a new world, the team he was with was ambushed by the Barrayaran military. He died from nerve disruptor fire when he distracted the Barrayarans with his stunner to allow the rest of the survey team to escape in their shuttle.
His corpse was later found by Captain Naismith and Ensign Dubauer, and buried by Naismith's captor Aral Vorkosigan. Naismith and Vorkosigan later arranged for a memorial marker placed on Rosemont's makeshift grave.