Dominetta Petacchi, known simply by her nickname "Domino", is the Italian mistress of Emilio Largo.
Born Dominetta Petacchi, she is an Italian beauty who went to school in England at Cheltenham Ladies' College. She later studied acting at the Royal Academy of Dramatic Art until being forced to return to Italy after her parents tragic death in a train wreck where she became an actress. She changed her surname to Vitali, a stage name. While in Italy she also became Emilio Largo's mistress whom she calls a "guardian" of no relation.
Bond meets Domino while in Nassau. She is staying on Largo's yacht, the Disco Volante, and believes Largo is in the area on a treasure hunt. For reasons she does not understand Largo makes her stay on land while he and his partners (whom she describes as shareholders) go prospecting for the hidden treasure. She also tells Bond that she has never been able to see the map that they use.
Although Bond is successful in engaging Domino in conversation, she snubs him, but later agrees to meet with him again when she returns to land. She also becomes testy when Bond uses her given name, Dominetta, and bluntly tells him to call her 'Domino'. When Bond and Domino meet again at the casino later, she has entirely changed. She tells Bond that she is tired of watching Largo show off and letting him use her. She explains to Bond that she is trapped like a bird in a gilded cage.
Domino later reveals that Giuseppe Petacchi is her brother who she hasn't seen for quite some time. Bond finds out that Largo had Petacchi killed after Petacchi had hijacked bomber on SPECTRE's behalf. He proves this to Domino, and recruits her as an ally to spy on Largo. Domino returns to Largo's yacht, the Disco Volante, with a geiger counter to verify the ship as the location of the two stolen nuclear bombs, however, she is uncovered and taken prisoner. Largo tortures her by burning her with a cigar for heat and then using ice cubes for cold.
Domino ultimately escapes as Largo attempts to carry out his plan. During a battle with Bond, while he is focused on Bond, she appears behind him and shoots him in the neck with a harpoon from a spear gun, avenging her brother and for what he had previously done to her.