Onboard the Defiant, Sisko and the crew pick up a distress signal and the voice of Captain Lisa Cusak, whose escape pod has crashed on a remote planet following the destruction of her ship. Although two-way communication has not been established, Lisa transmits her voice constantly as the crew begins the six-day trip to rescue her. O'Brien listens to the sometimes-amusing monologue and is surprised when she — having overheard a conversation between him and Kasidy Yates — suddenly speaks to him. Both realize contact has been established, and Lisa finally knows she will be rescued.
The stranded captain reveals she has been giving herself triox injections to compensate for the excess carbon dioxide in the atmosphere, but there is not enough to last until the Defiant arrives. Dr. Bashir advises lowering her dosage, hoping her body will be strengthened enough to help her survive. In the meantime, the crew members agree to take shifts talking to Lisa to keep her alert.
Proving to be as good a listener as she is a talker, Lisa has a great sense of humor and a refreshingly positive attitude. She advises Sisko on his romantic problems, helps O'Brien cope with his anger over the war, and even gets Bashir to forget about his work and loosen up. When Lisa runs out of triox, Bashir realizes she cannot survive more than two days — and the Defiant is still three days away.
Determined to save his new friend, Sisko gives the risky order to deplete the phaser reserves and use the extra power to increase the ship's speed. They reach the planet's orbit just as Lisa loses consciousness, but there is more bad news — the planet is surrounded by an energy barrier the Defiant cannot penetrate.
Sisko, O'Brien, and Bashir put their lives on the line to break through the barrier in a shuttle pod. They are able to reach the planet's surface and locate the crash site, but when they enter the cave where Lisa has taken shelter, they find a skeleton — Lisa has been dead for over three years. O'Brien surmises that the energy barrier must have time-shifted the radio signals, enabling the captain to contact the Defiant crew three years in the future and their messages to travel back to the past. Although Lisa was dead all along, the crew members feel the loss and take her back to Deep Space Nine for an Irish wake among friends.