He drags Jex from the jail, chases him through town and then shoves him over the borderline. Where just moments ago we saw him championing the legal system, the Doctor is now all about making the judgment himself. When Jex tries to cross back into town, the Doctor grabs a gun. He aims it at Jex's face. Isaac calls his name and the Doctor spins around to face him, gun still at the ready. Suddenly Amy has a gun of her own. She shoots into the air. "Let him come back, Doctor!" It's a demand, not a plea. This moment of seriousness is interrupted when she keeps accidentally firing the gun like she's Homer Simpson. Then it's serious again as the Doctor goes off on a rant. "Every time I negotiate, I try to understand, well, not today. No. Today I honor the victims first -- his [points at Jex], the Master's, the Daleks -- all the people who died because of my mercy!" Amy stays calm. "See, this is what happens when you travel alone for too long." He should really look into getting another dog. Amy tells him they need to be better and it finally reaches the Doctor.
He lets Jex cross back into town, but the Gunslinger has arrived. Jex recognizes him through all the implants. "Kahler-Tek, isn't it? I remember everyone's names, even now." He promises he'll never hurt anyone else, but the Gunslinger has run out of patience. Isaac jumps in the way, taking the shot that was meant for Jex. The Doctor kneels down beside him. "Protect Jex," Isaac says. "Protect my town. You're both good men... you just forget it sometimes." He passes his badge on to the Doctor and dies. Nooo! Ben Browder, don't go! The Doctor instructs the townspeople to take Jex back to the jail and turns to the Gunslinger. "This has gone on long enough." The Gunslinger seems sad, although it's kind of hard to tell when half his face is a video camera. Nonetheless, he gives the town until noon the next day to hand over Jex. "Or I'll kill you all."
Night. Some people want to hand Jex over to the Gunslinger. Others want to protect their friend. They show up outside the jail to confront the Doctor. He all but wags his finger at those in the "hand him over" camp, even though he could have been their leader not long ago. An 18-year-old kid threatens to shoot him. The Doctor talks him out of it: "Don't you see? Violence doesn't end violence -- it extends it." It's more that the Doctor doesn't want the town to turn into a bunch of killers than he's really protecting Jex, although he's doing that too, because of his promise to Isaac. Eventually, the crowd disperses.