Robert Path (Stallone) is at the top of his game - the most respected and top-seeded assassin in the world, but he wants out. To reach the top, you have to kill the competition - as Path did 10yrs earlier to his Russian mentor and friend which has burdened him with guilt ever since. Now there is a younger, more ruthless assassin on the scene, Miguel Bain (Antonio Banderas), and they have both been offered a hefty contract to eliminate a hacker named Electra (Julianne Moore).

When Electra finally realises that Path is not out to get her and starts to trust him, they double team and strike a new deal with the anonymous agent who offers the contracts - $20million in exchange for the disk, after the earlier drop-off shows the agent to be a double-crosser.
  They agree to wire transfer the money to a foreign bank, the same place before where Path killed his Russian friend, and exchange the disk through the bank manager.  Bain is offered the contract to kill Path by the agent.
  Path figures Bain will show up, and also will use the same location to hideout across the street that he used 10years previously, but he has a plan.
  He arrives at the bank early without giving them advance warning, and is happy to wait all day while they go through the motions to get the cash ready for him to take away.  Electra is sat outside telling him stories through a mic and ready to inform him about Bain's movements.

Bain becomes increasingly frustrated under the glaring sun, sitting in his hideout for hours watching intently on the bank's exit for any sign of Path.  Finally he is so agitated that he walks into the bank to confront him.
  Electra seizes her moment to get into the hideout and find his sniper rifle, but falls through the rotten floorboards and is trapped.

Bain gets back into position. Path exits the bank, hides behind a pillar, and tries to get Electra on the mic but doesn't hear a word.
  Bravely he steps out to face his enemy - but Electra manages to shoot Bain with a silenced handgun. As he dives for cover, Path gets over to the old hotel and they fight.
  Path is winning, shots are fired and he thinks Miguel is dead.  His old Russian friend walks in, tells him the secret that he was the agent all along, and wore metal across his heart all those years ago to deflect the bullet.
  Bain, from the floor, opens fire on the Russian before he can shoot Path.
  Bain and Path square off, but decide to go their own ways.  Bain has a change of heart and is about to shoot Path in the back, but using a reflection in Electra's sunglasses Path fires a few rounds back under his jacket, taking out his enemy, meaning he's still number one.