Dr. Karin Chakwas is a recurring character in the "Mass Effect" series as the human doctor of the SSV "Normandy", and later the "Normandy" SR-2. Dr. Chakwas survives the destruction of the SSV "Normandy" in "Mass Effect 2", and later accepts Cerberus' offer to join Shepard in their fight against the Collectors, getting a position on the "Normandy" SR-2 as the ship's Chief Medical Officer. Dr. Chakwas returns in "Mass Effect 3", provided she survives the suicide mission in "Mass Effect 2". She may be recruited back to the "Normandy", or be convinced to stay at the Citadel and assist in the war effort.