When Marty McFly and Doc Brown arrived in 1927, they posed as a rival gangster named "Zipper" McFly, and his brew master Dr. Brown. Marty staged a fake police raid using sound effects with a key ring from 1991. This allowed Doc to get the distilled juniper berries he needed to cure the eye infection from which his dog Einstein suffered. It also allowed Marty to free his relative Jim McFly from being employed by gangsters.