Troi wakes in a darkened room suffering from the effects of some sort of drug. She asks the computer for the lights without any effect. She stumbles to the wall control and the lights come up to reveal her face altered to look Romulan.
The ship's first officer, Subcommander N'Vek, soon walks into the room. He tells Troi that she is on the Imperial Romulan Warbird Khazara and is to masquerade as Major Rakal of the Tal Shiar, the Romulan secret police. Beyond that, N'Vek only tells her that her assistance is needed, and that her only chance of survival is to listen to him. Troi agrees for the time being and goes to meet the ship's captain, Commander Toreth.
Toreth has an extreme dislike for the Tal Shiar and is unhappy about the clandestine nature of their mission. While Troi is initially taken aback by Toreth's constant questioning, she soon settles in and plays her role as Rakal quite well, threatening Toreth with interrogation unless she follows orders. Troi then informs Toreth that she is to take the Khazara into the Kaleb sector once they have finished loading their cargo, as N'Vek had instructed her earlier.
Meanwhile, back on the Enterprise, Ensign DeSeve transports on board. DeSeve defected over to Romulus as a young man, but decided to return to the Federation. While the Federation plans on arresting DeSeve for treason, Picard decides to listen to him when he says that he is delivering a message from Ambassador Spock. A Corvallen cargo ship will be arriving shortly in the Kaleb sector with a cargo which is very important to the Federation. He requests that the Enterprise be there to meet it.
Picard is reluctant to take this advice at first, and wants to ask DeSeve some questions before doing anything. When he asks DeSeve why he defected to Romulus and why he decided to return, DeSeve says that the Romulans have a very clear idea of what is right and what is wrong, but that these concepts finally lost their appeal, and while it took him a long time to figure all of that out, DeSeve finally did and gave his allegiance back to the Federation. Picard is satisfied with DeSeve's explanation, and issues orders for the Enterprise to proceed to the Kaleb sector.
On the Khazara, Troi goes with N'Vek to the cargo bay and discovers that the cargo is actually Romulan passengers in stasis. Vice Proconsul M'ret and two of his top aides plan on defecting to the Federation as a protest against the ruthless policies of their government. N'Vek, also a part of this plan, is providing an underground railroad for the three of them to defect. Troi deduces that he is working for Ambassador Spock but she wonders if a Romulan officer might be better suited for the plan. N'Vek however insists that should this part of the scheme fail, a Starfleet officer will be necessary.
Troi and N'Vek go to dinner with the rest of the Khazara's officers, and Toreth starts digging into Troi's background, trying to provoke her. Troi argues back which results in Toreth revealing that her father was executed by the Tal Shiar over mere idealism. Troi ends the argument by saying, "I don't need your devotion, commander-just your obedience," to which Toreth responds, "That's all you have."
The ship meets the Corvallen freighter in the Kaleb sector but Troi senses that they have no intention of keeping their promise to deliver the cargo. As soon as Troi tells this to N'Vek, he fires on the freighter, destroying it. When Toreth demands to know why he fired, N'Vek responds that he was obeying Major Rakal's orders. Troi informs Toreth that she identified the freighter captain as a known Federation spy. Toreth informs her that she deplores the loss of the freighter and plans to make an official record of the incident in her log. Troi then orders Toreth to cloak the ship and hold position, and storms off the bridge.
The Enterprise, not knowing that N'Vek's initial plan has failed, arrives in the Kaleb sector but does not find the freighter it was supposed to meet, nor a trace that it was ever there. Picard asks DeSeve what happened but DeSeve says that he does not know. He does say that his message did not come directly from Spock, but from another man whom DeSeve trusts completely. It is also determined that the freighter has minimal speed, and cannot be more than fifteen light years away. Picard orders a search for the freighter.
On the Khazara, Troi confronts N'Vek in private over the death of the freighter's crew. N'Vek insists that he did what he had to do, and predicts that those Corvallens will not be the last to die for this mission. Troi and N'Vek agree to put that argument aside and continue with their plot. N'Vek says that they must go to the Federation Starbase on Draken Four, finally revealing why he needed a Starfleet officer: only they can provide the necessary access codes to get past the "listening posts" and sensor nets on the border between Romulan and Federation space.
On their return to the bridge, Troi informs Toreth about the new plan to bring the Khazara into Federation space. Toreth is dead against the plan, knowing how dangerous it is. She reluctantly complies after Troi calls her a coward. The crew sets course a for Draken Four, but suddenly they detect the approaching Enterprise.
Toreth admits that the presence of the Enterprise vindicates Troi's earlier action and that they are obviously here to look for their missing spies. She initially decides to leave right away but N'Vek cautions that the radiation from the destroyed freighter could make them detectable to the Enterprise if they engage their warp engines. Toreth orders the ship to be moved clear of the debris field before going to warp.
On the Enterprise, meanwhile, the crew discovers the remains of the Corvallen ship. Data concludes from a debris scan that the ship was destroyed by Romulan disruptor fire. Wary that the Romulans may be still be in the area Picard orders the crew to battle stations. Back on the Khazara, Troi tells N'Vek they should get a message to the Enterprise. N'Vek initially refuses believing it to be far to dangerous. Troi persists and N'Vek finally concedes that the chief engineer is a sympathiser and may be willing to make a small imbalance in the engines that would make the ship detectable. Troi orders him to do so, saying she will expose him as a traitor if he does not cooperate. N'Vek reluctantly agrees.
The Enterprise picks up the distortion and follow it. On the Khazara, Toreth demands that the cloak be checked but N'Vek reports it is working correctly. Furious that her ship is being tracked, Toreth decides she has no option but to attack the Enterprise.
On the Enterprise DeSeve warns Picard that the Romulan commander may turn and attack them if it becomes clear they can't escape undetected. Toreth orders the ship to move toward the Enterprise, reasoning that if the Federation ship can indeed detect them, they will move to avoid a collision, at which point Toreth will decloak and destroy the Enterprise.
The Enterprise backs away when DeSeve can give no explanation of the collision course. Toreth, on the verge of ordering the crew to attack, is overruled by Troi, who relieves her of duty. Troi then orders the crew to decloak the ship and open a channel to the Enterprise.
The Enterprise responds to the hail and the bridge crew is shocked when Troi appears on the screen but gives nothing away. Troi apologises for the incident with the Corvallen ship and offers to beam aboard to sort everything out. Picard acknowledges Troi's offer, and asks Worf to put a transporter lock on Troi and prepare to beam her aboard.
On the Khazara, the crew reports that the Enterprise is lowering her shields. Troi orders N'Vek to fire on the Enterprise. The ship takes a direct hit but suffers no damage. Instead, the three Romulans appears on the bridge, who DeSeve identifies. The crew on the Khazara report that the disruptors were using minimal power and were used to disguise transport of cargo to the Enterprise. Toreth understands right away that Troi and N'Vek are traitors, and reaches for her weapon, not remembering that N'Vek had confiscated it earlier. N'Vek reaches for a weapon of his own but is killed by the ship's helmsman. Toreth orders the crew to cloak the ship and set a course for home. She vows to interrogate Troi and possibly execute her but before she can take action, the Enterprise beams Troi away.
Back on the Enterprise Troi gets her own face back and is reassured by Picard that N'Vek's sacrifice was not in vain.