Sommen served as an operative for the Alliance to Restore the Republic throughout the Galactic Civil War. During an assignment involving covert entry, Sommen took on the role of a medical engineer employed by the Neuro-Saav Corporation located on Tauber. He shared a design station with Dr. Cinto Alaras. The Task Force on Alliance Security of the Rebel Alliance held concerns that Alaras was attempting to misappropriate Sommen's work, potentially exposing his true identity in the near future.