Cullen takes on Chang and his men in order to save Mei.
Mei sits at a table inside the Washoe City saloon. She looks out the window and sees Chang ride into town. Chang heads straight for the saloon.
Gun drawn, Chang enters the saloon. Mei is nowhere to be seen. Chang tells the bartender that he's looking for a young man who might have passed through. Under the bar, Mei shoves her pistol into the barkeep's groin. The barkeep nervously says the town's been empty for weeks since the boom ended, but a man came through earlier headed East. Chang turns and Mei takes action. She jumps up, points her pistol at Chang's head and cocks it. Mei orders the barkeep out and tells Chang to drop his gun. Chang obliges, but warns her that Sze Yup men are everywhere. They're interrupted by the saloon door opening slowly -- it's Cullen. Chang starts to welcome him, but Cullen abruptly fires a bullet through Chang's head. Cullen sighs and walks out.
Inside, Mei watches through the windows as Cullen eliminates all of Chang's men. When the killing is over, Mei takes Cullen's hand and they walk into the street together.