Set in the 24th century, the series follows the adventures of the crew of the Federation starship Enterprise. In this episode, Lt. Cdr. Geordi La Forge (LeVar Burton) is trapped on an inhospitable planet hazardous to human life with a Romulan. The two adversaries must work together if they wish to survive. Aboard the Enterprise, Lt. Worf (Michael Dorn) is faced with a conflict between his duty as a Starfleet officer and his Klingon prejudice against Romulans, and Captain Picard (Patrick Stewart) must contend with a Romulan warbird intent on recovering their own personnel.
The Federation starship Enterprise, under the command of Captain Jean-Luc Picard, follows a distress signal and finds wreckage of a Romulan craft on a hostile planet, Galorndon Core, near the Neutral Zone. Commander Riker (Jonathan Frakes), Lt. Worf, and Chief Engineer La Forge transport down to investigate but find most of their equipment to be non-functional due to the extreme electromagnetic interference on the planet. They find the craft and a Romulan survivor, barely alive. Riker and Worf return to the ship with the Romulan, while La Forge continues to search the craft; however, he falls into a hole.
Aboard the Enterprise, Chief Medical Officer Dr. Crusher (Gates McFadden) needs ribosomes to prevent the Romulan from dying. She reviews the crew's medical records to find a matching donor. The bridge crew postulates what happened to La Forge, and the weather on the planet prevent from them from transporting down or using a shuttle craft to look for him. Wesley Crusher (Wil Wheaton) suggests adapting a probe to emit neutrino pulses that would guide La Forge, through his VISOR, to the next beam-out site. As they launch this, they discover a nearby Romulan warbird, captained by Commander Tomalak (Andreas Katsulas). On the Enterprise, Picard tells Riker that, if the situation is mishandled, "history may remember Galorndon Core alongside Pearl Harbor and Station Salem-One, as the stage for a bloody preamble to war." (No further information about "Station Salem-One" has ever been provided in Trek canon, so it is not known which war Picard is referring to, nor when it occurred.)
La Forge climbs out of the pit and catches the neutrino pulse on his VISOR. However, he is captured by another Romulan, Bochra (John Snyder). Bochra explains that he is losing feeling in his legs due to an injury from the crash. La Forge explains how his visor can lead them to be transported away, but just as he does so, his VISOR gives out. La Forge is left hopeless until Bochra provides him with an idea of using the VISOR and his tricoder as a directional guide to the beam-out site. La Forge, still blind, guides Bochra through the modification process and then carries him as they work towards the beacon.
On the Enterprise, Worf is the only matching donor for the injured Romulan, but he refuses to help and the Romulan refuses to accept any donation from a Klingon. As Picard dresses down Worf for not making the donation, they find this is all for naught as the Romulan has died. Soon, Tomalak arrives with his Warbird's weapons charged, just as the beam-out window on the planet opens. Picard orders his shields up and tries to negotiate with Tomalak, but soon is forced to reveal that the Romulan is dead. Tomalak considers this a breach of the treaty and prepares to fire. The Enterprise crew scans La Forge and another life form at the beam out location, and Picard orders the shields down to allow them to be beamed onto the Bridge. La Forge and Bochra are safe, and Bochra explains to Tomalak that while he gave the Enterprise crew no information, they were not responsible for the crash nor did they harm him. Tomalak stands down, and it is decided that the Enterprise will escort Tomalak back to the Neutral Zone after they return Bochra to them. After Tomalak agrees to be escorted to the Neutral Zone, both ships head in different directions.