Sarah Anne Tordon-Longknife was the first daughter of Gen. 'Trouble' and Ruth Tordon. She married Alexander Longknife and they had one son William. She was killed in a vehicle accident when the driver of a truck had a heart attack and slammed into the car she and Alexander where in. The autopsy on the truck driver showed no alcohol or drugs in his system, however the blood wasn't tested until two hours after the accident. Kris Longknife doesn't think it was truly an accident.
Sarah's death was sixty years or more before the action in Intrepid.