 Billy and Suzy throw rocks at a bottle. Suzy throws first so that her rock arrives first and shatters the glass; Billy’s rock sails through the air where the bottle had stood moments earlier. Without Suzy’s throw, Billy’s throw would have shattered the bottle. However, Suzy’s throw caused the bottle to shatter, while Billy’s throw is merely a preempted potential cause. This is a case of late preemption because the alternative process (Billy’s throw) is cut short by the main process (Suzy’s throw) running to completion.