members of the McFly family, including Buford "Mad Dog" Tannen (also portrayed by Wilson, in Part III), who is one of Hill Valley's outlaws during the 1880s. McFly family Dave McFly David "Dave" McFly (portrayed by Marc McClure) is the eldest child of George and Lorraine McFly. In 1985, before Marty went to 1955, Dave works at Burger King, but in the post-time travel 1985, he wears a suit as a nondescript white-collar worker for an accounting firm. In a deleted scene from Part II, the alternate 1985 timeline shows that Dave is an alcoholic and a gambling addict following George's death and Lorraine's second marriage to Biff Tannen. Linda McFly Linda McFly (portrayed by Wendie Jo Sperber) is the middle child and only daughter of George and Lorraine McFly. In 1985 before Marty went to 1955, Linda is having boy trouble and it is unknown if she is in college or has a job. In 1985 after Marty went to 1955, Linda works in a boutique and has gained the attention of many boys. Seamus and Maggie McFly Seamus and Maggie McFly (portrayed by Michael J. Fox and Lea Thompson) are Irish immigrants and the paternal great-great-grandparents of Marty McFly. In Part III, Marty is befriended by Seamus and Maggie. While Maggie does not trust the "strange young man", Seamus has a familiar feeling about him and believes that helping him is the right thing to do. They have a son named William (Marty's great-grandfather). Much like his descendants, Seamus is harassed by a member of the Tannen family, Buford Tannen. He also had a brother, Martin, who was fatally stabbed prior to the film's events. Maggie McFly is played by Lea Thompson, who also plays Marty's mother Lorraine, even though Maggie is not an ancestor of Lorraine; in a DVD commentary track for Part III, Bob Gale states that the creative team considered it important to include Thompson in the film, and he imagines that McFly men are simply "genetically predisposed" to be attracted to women who look like her. William McFly William "Willie" McFly (voiced by Michael J. Fox in Back to the Future: The Game) is the son of Seamus and Maggie McFly as well as Marty's great-grandfather. Arthur McFly and Sylvia Miskin Arthur "Artie" McFly and Sylvia Miskin (stage name "Trixie Trotter") are Marty's grandparents introduced in Back to the Future: The Game and voiced