Captain Lisa Cusak was a 24th century Human Starfleet officer born in 2320. Early in her career, Cusak was attached to the Andorian Embassy. While there, she started a long relationship with a man who worked at the Andorian Agricultural Ministry.
She had two sisters, both of whom were teachers. She was once posted on the same starbase as one of her sisters, but found this difficult, later using it as an example of why she had to keep her personal and her professional lives separate.
Some time after this, Cusak was given command of the USS Olympia. The ship left the Federation in 2363 on a mission to explore the Beta Quadrant. In 2371, when the ship was returning home, they discovered a planet surrounded by an energy barrier in the Rutharian sector. When the Olympia scanned the planet, the ship was hit by a surge of metreon radiation which disabled its engines and caused the ship to crash. Cusak was the only survivor.
Her distress call was received by the USS Defiant. It was initially a one-way broadcast; Miles O'Brien listened to her for some time, feeling it was the least he could do. She reminded him of his cousin as she talked about her home and family.
Eventually, he was able to make contact with her. As the Defiant made its way to the planet where she crashed, she conversed with Sisko, Julian Bashir, and O'Brien, telling them stories of her life and listening to their problems.
When the Defiant arrived at the planet in 2374, they discovered that she had been dead for three years, two months from carbon dioxide poisoning. The metreon radiation had distorted her signal, transmitting it into the future. The return signal was similarly distorted, sent back through time. Captain Sisko decided that the body was to be taken back to Deep Space 9, where the crew held a wake. Despite having never met her, the crew believed she had made a real difference to their lives just through "the sweet sound of her voice." (DS9: "The Sound of Her Voice")