"After a while, all we had in common were the stars, our dreams...You can go far on a dream..."
- – Mariah
In the mid-22nd Century, she and her husband Will both worked for a commercial research outfit. They volunteered for a long duration deep space flight in cryonic freeze aboard the USS Copernicus, a ship designed to search space for any signs of intelligent life and home in on it. They did so despite some marital discord (they had split up a half dozen times, always getting back together).
She was re-animated in 2259 when her ship found its way to Babylon 5 in the Euphrates Sector. She awoke in the station's Medlab to find her husband dead and the fact that Humans have long since colonized space, encountering hundreds of alien races along the way. She meets Dr. Stephen Franklin, who tries to help her get acclimated to her new surroundings and come to terms with the death of her husband. He eventually explains that her husband was murdered. This leaves her all the more confused and frightened. She begins to remember dreams she had while in stasis, terrifying dreams about a monstrous being. She soon realizes that something came aboard her ship, a Soldier of Darkness, that murdered her husband and fed off her. Sensitive to its presence, she helped Security Chief Michael Garibaldi track it down, where it was killed in a firefight with security personnel.
Afterward, Mariah decides to return to Earth so she can both grieve for Will and properly heal after all that has happened. She kisses Dr. Franklin good-bye, hopeful that one day she might come back.