The crew of the Enterprise discovers about 6,000 humans on a Delphic Expanse planet living in settlements that are similar to those of the Old West. Archer, T'Pol and Trip disguise themselves and head down to observe, hoping to learn how these settlements came to be. Reporting from Enterprise, Reed notes that scans indicate that there's also a nearby settlement of aliens.
Observing the town, Archer manages to learn that there's long-standing animosity between the humans and the aliens, the Skagarans (called "Skags" by the humans). In particular, the malicious Deputy Bennings seems to be set on persecuting the "Skags" any way he can. For their part, the Skagarans are treated like slaves by the humans. Archer befriends the local schoolteacher, Bethany, who seems to be the only human with compassion for the Skagarans. In fact, she is secretly teaching Skagaran children at night, even though it's illegal. Intrigued, Archer accompanies her to one of her lessons. Meanwhile, T'Pol and Trip have discovered what appears to be the remains of a spacecraft. They retrieve some data chips from the wreckage and head back to Enterprise to analyze them.
As Archer observes Bethany's lesson, she is suddenly interrupted by Bennings and his men. The deputy followed Bethany and the captain to the Skagaran settlement, and now he's prepared to arrest them for teaching the aliens. In jail, Bethany tells Archer more about the planet's history. Three hundred years ago, the Skagarans used their spacecraft to bring humans to the planet, using them as slaves to build new colonies. One man, Cooper Smith, staged a rebellion, burning the Skagaran ship, destroying the Skagaran weapons and killing many of the aliens. Smith eventually wrote laws keeping Skagarans from going to school, owning property and marrying. Now, the Skagarans are essentially slaves.
Bethany's story is interrupted when Archer is summoned by the town sheriff, MacReady. MacReady is a more reasonable man than Bennings, but he believes that protecting the humans means keeping the Skagarans subservient. He tells Archer to leave town. Archer agrees, but first he breaks Bethany out of jail. As they attempt to escape, Bethany is shot and critically wounded, forcing Archer to beam her up to Enterprise with him in front of the confused townspeople.
On Enterprise, Phlox tends to Bethany and makes a startling revelation: she's one quarter Skagaran. Having studied the data chips, Hoshi adds that they confirm Bethany's story. While Archer doesn't want to just leave the humans to this planet, he knows that they can't bring them back to Earth until the Xindi have been dealt with. Determined to come up with a solution, he heads back down to the planet with Reed, T'Pol and a team of MACOs. The townspeople are shocked to see a shuttlepod, but Archer manages to have a peaceful meeting with MacReady. MacReady believes Archer's story and the two men seem to be in agreement. Just as Archer is preparing to take MacReady up to Enterprise, Bennings and his men attack, wounding the sheriff and staging an all-out brawl with the Enterprise crew. Luckily, the crew manages to fend them off and Archer subdues Bennings.
With MacReady ready to make changes to the town, Bethany returns from Enterprise. Using a Starfleet PADD, she teaches all that she's learned from Archer to a classroom of humans and Skagarans.