DS9 Season 6 Episode 13 Far Beyond the Stars

Plot

Distraught by the death of a friend in the Dominion War, Captain Benjamin Sisko contemplates leaving Starfleet. He begins experiencing hallucinations of 20th-century New York City, and is suddenly taken over by his vision: becoming Benny Russell, an African-American science fiction writer in 1953, who is not conscious of his life in the 24th century.
Russell encounters people who bear the likeness of people from Sisko's life on Deep Space Nine, such as a newsstand vendor who resembles his son's friend Nog. His fellow writers for the magazine Incredible Tales include Albert Macklin (Miles O'Brien the short-tempered, left-wing Herbert Rossoff (Quark and married couple Kay Eaton (Kira Nerys) and Julius Eaton (Julian Bashir). The magazine's illustrator Roy Ritterhouse (Martok) shows them sketches to be used in an upcoming issue; Russell is drawn to one of a space station resembling Deep Space Nine, and offers to write the story for it. Magazine editor Douglas Pabst (Odo) tells Kay (who writes under a gender-neutral name) and Russell they are to be excluded from upcoming staff photos, as the magazine's readers might object to a woman and a "Negro" as science fiction writers.
That night, Russell is harassed by two white police officers, Ryan (Dukat) and Mulkahey (Weyoun). He encounters a street preacher (Joseph Sisko) who seems to be speaking directly to him, imploring him to "write those words" in the name of "the Prophets". Russell goes home and begins to write.
Some time later, he finishes his story "Deep Space Nine", about the black captain of a space station. His girlfriend Cassie (Kasidy Yates) doubts his ability to earn a living as a writer, but is faithful to him despite flirtation from baseball player Willie Hawkins (Worf). A young hustler, Jimmy (Jake Sisko), laughs at Russell's idea of "colored people on the Moon".
At the magazine, the entire staff loves his story, including Pabst's secretary Darlene Kursky (Jadzia Dax however, Pabst refuses to print it on the grounds that the readers won't like a story with a black protagonist. But Russell keeps writing sequels to the story, and Macklin proposes a compromise: frame the story as just a dream, which Pabst reluctantly agrees to. While Russell and Cassie are out celebrating, Jimmy is shot and killed by officers Ryan and Mulkahey. When Russell protests, they beat him savagely.
On his first day back at the office weeks later, Russell is eager to see his story in print. Pabst arrives empty-handed: the owner has pulped this month's issue rather than publish a story featuring a black hero, and Russell is fired. Russell breaks down, screaming that they cannot destroy his ideas and that the future he envisions is real. As he is taken away by an ambulance, the preacher appears next to him, and tells him that he is both the dreamer and the dream.
Sisko wakes up back on the station. He is deeply moved by his vision and wonders if somewhere, far beyond the stars, Benny Russell is really out there, dreaming of them.