Dean Domino

During the events of Fallout: New Vegas add-on Dead Money, Father Elijah forces The Courier to retrieve three other bomb-collared individuals to aid in his heist on the Sierra Madre. Among the three is Dean Domino, a ghoul who had manipulated these events so he could rob the vault for himself.

Background
Prior to the Great War, Domino had been a grand singer and performer, doing tours across the United States and Europe when he was invited to put on a show at the Sierra Madre casino at the behest of Frederick Sinclair. However, Domino soon became envious of Sinclair's wealth and efforts that he formulated a plan to rob him, so as to "take Sinclair down a peg" by taking everything from him. He worked alongside his former lover Vera Keyes, whom Sinclair had become infatuated with, and threatened to expose her Med-X addiction (caused by her terminal illness) unless she went through with the plan. Before his plan could be enacted, his final performance at the Sierra Madre's theater The Tampico was cut short when the bombs dropped and a massacre ensued when the security holograms activated.

Domino survived, but became entrapped within the area surrounding the Sierra Madre. Unwilling to let go and obsessed with robbing the casino of its treasure, Domino eventually degraded into a ghoul and spent the next two hundred years plotting a way to enter it.

Dead Money
At some point, Domino is attacked and bomb-collared by the Nightkin Dog on the orders of Father Elijah. Following The Courier's unwilling recruitment, Elijah orders The Courier to collect three individuals: Dog (or God), Christine, and Domino. When The Courier first meets Domino, the ghoul instructs him to sit down in a chair nearby, only to then reveal that the chair has a shaped explosive attached. After convincing Domino to join them, Domino takes the opportunity to further his plans when he allies himself with The Courier. After The Courier gets Dog (or God) and Christine to meet up at the fountain outside the gates, Domino directs The Courier to escort him to his position at Puesta del Sol south in order to trigger the Gala Event that will open the Sierra Madre. Domino only partakes in this operation once The Courier activates security holograms to keep him protected from Ghost People that lurk around the perimeters.

Elijah then instructs The Courier to kill Domino in The Tampico once his use has run out. Depending on how The Courier treated Domino throughout the add-on. If The Courier did not bruise Domino's ego, the ghoul will direct The Courier along The Tampico's backstage area to deactivate the security holograms, whereas he will simply attempt to misdirect or condemn The Courier to death if they confronted him prior to this. After deactivating the security holograms, Domino reveals his true intentions when he states that he had developed this plan in order to achieve his goal of robbing everything Sinclair had. Even more horrifically, Domino reveals that he was the one who forced Christine into the Auto-Doc that brutally tortured her and severed her vocal chords. He had done so in order to use Christine as a vessel for a module of Vera Keyes' voice. With this, he would be able to force her to activate the secret elevator that would lead to the vault and make off with the riches.

Domino's ultimate fate depends again on how The Courier treated him. If The Courier regarded him with respect and curried his favor, Domino reveals his plan and sends The Courier to rob the vault in his place. Following that, Domino will eventually leave Sierra Madre, ultimately getting away with his manipulations. If The Courier proved confrontational, Domino will attempt to betray and murder The Courier while holding the key to the exit. The Courier will then be forced to kill Domino to retrieve the key, and then immediately evacuate the area before Domino's bomb collar explodes and kills The Courier with him.

Unknown to Domino, Sinclair had caught onto his plans and had designed a trap in the vault to permanently seal Domino away. Alive or dead, Domino never reaches the vault, although this trap can ultimately be used to entrap Father Elijah once and for all.