There are even a few cases in which the double’s warning is supposed to have saved a person’s life. Alex B. Griffith believed that his double saved a person’s life - twice.

The first time was in the summer of 1944, during World War II. Griffith was an infantry sergeant leading a patrol in France. There was no sign of danger, and Griffith and his men felt quite safe.

Then Griffith saw a figure on the road ahead. The figure was his double, and it was waving its arms and appeared to be shouting, though no words could be heard. The figure was obviously trying to make Sergeant Griffith and his men stop. But no one aside from Griffith could see the figure. Then men were surprised and puzzled when their sergeant abruptly ordered them to turn back. He didn’t explain why. He couldn’t. He just knew that if they went any farther down that road they would be killed.

As he sat on the ground trying to figure out what to do next, Griffith saw an American supply vehicle pass and head down the road to the spot where he had seen the double. There was a sudden burst of machine-gun fire, and the vehicle went wildly out of control. Its driver had been killed in the volley. Somewhere up ahead a German machine gun was hidden to guard the road. If Sergeant Griffith and his men had gone any farther, they would have been gunned down, just as the vehicle had been.

Twenty years later, Griffith saw the double again. It wasn’t Griffith as he was in 1964, but Sergeant Griffith as he had been in 1944. Griffith and his family were out on a hike in the woods. There had been a tremendous storm the night before, and the winds were still gusty.

The little group rounded a bend in the trail, and there was the figure of the young Sergeant Griffith in uniform, waving its arms and shouting wordlessly, just as it had done on the road in France. As before, no one else saw the figure, but Griffith knew what the warning meant. He instantly told his family to stop and turn back.

A few seconds later a huge tree, weakened by the storm, came crashing down into a clearing where Griffith and his family would have been had it not been for the warning.