Commander Shran is forced to abandon ship, as his ship is destroyed by what appears to be a Tellarite vessel. Meanwhile, Archer is preparing to transport the Tellarite contingent to Babel One for a peace conference with the Andorians.
After receiving the Tellarite ambassador aboard, Enterprise changes course to answer an Andorian distress call. They do not arrive in time to save the ship, but bring aboard escape pods carrying Shran and his surviving crew. Shran, enraged over the treachery of the Tellarites, becomes even more incensed when he learns that the Tellarite delegation are on board Enterprise.
The Andorians and Tellarites begin to argue and accuse each other of wrongdoing when Enterprise is attacked by what seems to be an Andorian ship. The ship, however, does not respond to Shran's orders to withdraw, nor does it conform to Shran's intimate knowledge of Andorian cruisers. This mystery is compounded when it is discovered that the ships responsible for the two attacks have the identical power signature.
Enterprise is able to track this attacking ship to where it is stopped to make repairs, and Trip, Malcolm, and two MACOs beam aboard. However, when the Romulans (who it is revealed to the audience are in command of the ship) open fire, Enterprise is only able to beam back the two MACOs before their transporter goes offline, and they need to retreat.
Analyzing the sensor scans of the attacking ship, Archer and T'Pol learn that it is equipped with holographic imagers that can make it appear like other types of vessels. They deduce that another species, such as the Romulans, may be behind a plot to prevent peace between the other enemy species in the quadrant. However, this realization may be too late, as violence has already erupted between the Andorians and Tellarites on board.
Meanwhile, the Romulans decide that they must do anything to prevent Trip and Malcolm from learning about this prototype ship. When they finally reach the bridge, they find it empty. The ship is being piloted remotely from Romulus.