Chev Chelios versus Bryan Mills...
Chev Chelios is searching for his heart.
Bryan Mills is searching for his daughter.
As it turns, the same people that stole Chelios's heart have Mills daughter.
They enter a run down building at the same time at opposite ends, and, after disposing of everyone inside, round a corner and face each other down. They raise their guns and CLICK, CLICK....their guns are dry.
Mills thinks Chelios has his daughter. Chelios thinks Mills has his daughter. It's a h2h battle, to the death.
Mills is at full strength, while Chelios is in berzerker mode, like when he recharged his artificial heart on the power breaker halfway through "Crank 2."