Cap and the Punisher find themselves fighting a personal war in South America where the U.S. has been sending defective weapons for the personal gain of a few high powered government agents.
Somewhere in Texas, a well-armed militia-looking group approaches a warehouse. Inside the warehouse, another group of well-armed people engage in an arms deal until Captain America's shield bursts through the open door, smashing the transaction. The thugs don't take kindly to Cap's interference and start shooting. During the fight, one of the thugs grabs a rocket launcher and shoots at Cap a few times until the rocket launcher explodes. Just before Cap cleans up the remaining villains, the secretive militia group swoops in and whisks everyone and everything away. Suspicious of everything, Cap takes a sample from the broken rocket launcher.
A news media transition informs us of tensions between the U.S. and a South American country called Medisuela, primarily because of the antics of its leader, General Navatilas. U.S. Attorney General Roger Mollech informs the press he is focused on bringing Navatilas’s crooked regime down, regardless of the political implications involved. Whisperings between him and his female aide tell us it is all insincere bluff for the media.
In New York City, the Punisher has tracked down the same arms dealer Cap encountered in Texas, only this time he is peddling narcotics. Unlike Captain America who pondered fighting for justice, the Punisher blows up the meeting, prepared to destroy everyone in it, while he thinks he is fighting a war, ready to kill with impunity. The arms/drug dealer escapes to the roof with the Punisher on his trail. A helicopter arrives to rescue the dealer, and Castle recognizes the military lingo they use, indicating the source behind this deal is much higher up on the political ladder than he originally thought. After a brief battle, Castle causes the helicopter to crash into a subway entrance, leaving the area in flames. The dealer escapes into the subway and onto a train with the Punisher on his trail. The Punisher eventually kills the dealer on the train, leaving his corpse for all the passengers to see. Committed to following the trail up as far as it goes, Castle ponders the reality he has accepted: he is fighting a war so others can go home – he has no more home, only the war. And he will fight it even on the steps of the Capitol building.
In Medisuela, Attorney General Mollech’s aide converses and schemes with General Navatilas, confirming their partnership, though we aren’t sure the whole extent or purpose of this arrangement. Captain America is starting to discover it back in the states, as his investigation into the arms deal reveals the rocket launcher exploded on purpose – the arms dealers were intentionally selling faulty equipment to Medisuela. Not only that, but the supposed governmental militia group did not warehouse the stolen goods but took the equipment themselves. Similar to the Punisher, Cap tells the people with whom he is working that he is doing it all for them and their wellbeing – though he is obviously more optimistic about it than Castle is. Cap tracks the equipment trail to the militia, even assaulting their airplane in midair before parachuting out to safety. After he departs, we learn the militia is also in league with Mollech’s aide.
The Punisher follows his end of the investigation to the same source, Mollech’s aide, who pretends to go along with him, posing as a whistleblower. A fake assault that ends badly further convinces Castle she is trustworthy, even when she says Captain America is behind the whole thing. A night shortly thereafter, Cap and his buddy descend the steps of the Senate speaking of the conspiracy when Cap notices a reflection on a roof in the distance, recognizing its significance immediately. Cap throws his friend behind him, and the Punisher shoots him.