In 2092, Sergeant Major Sullivan, aged 28, attended the grand opening of a museum housing previously looted antiquities recaptured from The Enemy. One such antiquity was an ornate, rather hefty cast iron light fixing. During a speech delivered by General Kahn, head of the United European Federation Army, the fixing came away from the ceiling and plummeted down onto Sullivan’s head, killing him outright.
The alternate history was that in 2092, Sullivan attended the same museum opening, but as an enemy operative. Thus, the antiquity killed General Kahn instead and started World War Three.
In 2093, scientists invented a time machine in both alternatives.