You know what had to be done, you watched as you chased down the enemy one last time, then the two cars collided.
As you woke up, your worst nightmare is there, not a monster or anything, just a human.
Your friend tries to attack, but he is shot immediatley and killed.
After going through some quick time events, you smash his face in with a brick and defuse a nuclear bomb that was about to destroy the entirety of New York.
The game then cuts to the second protagonist, writing in a book, the door is knocked on, and he grabs his pistol.
Credits roll.
The end
Bloody hell it's hard to right dramaticly without context.