Fifty-Fifty O'Brien

Winchester Remington Smith is a crack shot. Problem is, surrounded by roller coasters and merry-go-rounds, his talent is going to waste, knocking down ducks in a carnival shooting gallery. Win wants some real action, and like Gary Cooper as Sergeant York, he's going to war—running off to join the U.S. Marines to fight a guerilla insurgency south of the border.

In the jungles of Central America, Win takes a different kind of roller coaster ride. Quick and quiet, he's now a runner. It's a vita...