Sisko returns from a trip to Bajor with the blueprint for an ancient space vessel that operates like a sailboat, using solar pressure for propulsion. According to legend, the Bajorans used these ships to explore their star system 800 years ago, even going as far as Cardassia. Sisko decides to build one himself to see if this was possible, and painstakingly recreates the vessel, determined to prove the design was spaceworthy. He hopes to have Jake join him on the adventure.
After initially declining his father's invitation, Jake reconsiders, and the two prepare to depart the station. Before they do, Gul Dukat warns Sisko against putting so much stock in a Bajoran "fairy tale" of ancient contact. Sisko feels Dukat is only interested in disproving the notion that the Bajorans, not the Cardassians, were the first people between the two races to develop interstellar travel.
The trip gets off to a smooth start, and both Sisko and Jake enjoy their time together. Jake seizes the moment to tell his father that he has been offered a writing fellowship in New Zealand, and Sisko is thrilled, yet distressed because those studies will take his son away from Deep Space Nine. But before they can discuss it, one of the ship's sails gives way, forcing them to struggle for control.
Sisko jettisons the sail, concerned about continuing. Jake reminds his father that the ancient Bajorans probably ran into similar problems and didn't give up. Convinced, Sisko decides to proceed on course. Jake then reveals that he plans to delay taking the fellowship for a year because of his concerns that Sisko hasn't had someone special in his life since his wife's death. Then, without warning, their ship is caught in an eddy of light that inexplicably takes it to warp speed.
After the ship is thrown free of the invisible current, Sisko discovers he has no idea where they are, and fears the eddy, composed of faster-than-light tachyons, has carried their vessel light years away. Suddenly, Gul Dukat informs the two that they have entered Cardassian space. As Sisko and Jake realize they just proved the same thing could have happened 800 years ago, Dukat reluctantly congratulates them on recreating the journey of ancient Bajoran explorers who did successfully reach Cardassia then, and welcomes the two with a stellar fireworks display.