At an Andorian command post under fire, Shran ("Shadows of P'Jem") tells his right-hand officer Tarah that the Vulcans want a cease fire. They don't trust the Vulcans, but Shran thinks that Archer will be a fair mediator. Admiral Forrest sends Archer to join with Vulcan Ambassador Soval to negotiate.
Archer and T'Pol go down to the disputed planet and meet with Shran. Archer refuses to be a messenger, and insists that Shran has to be more flexible. Returning to Enterprise with one of three Vulcans, the Andorians have detained, Archer also tells Soval to be more flexible -- forcing Soval to agree to meet with Shran on the planet.
The shuttle pod with Archer, T'Pol, and Soval is shot down. They are pinned under phaser fire and Soval is shot, but not mortally. Up in space, Trip has to literally put Enterprise between Vulcan and Andorian ships that are ready for a fight.
With T'Pol and Soval providing cover fire, Archer takes out the two snipers -- which include Tarah. Upon Shran's questioning, it's revealed that Tarah is one of many Andorians who think the only way to win is to fight the Vulcans, not talk.
Back on Enterprise, Archer helps broker progress in negotiating the cease fire. He's lived up to Shran's expectations, and even Soval thinks that Archer wasn't, "overly meddlesome."