Alison Elizabeth "Ali" Larter (born February 28, 1976) is an American actress. She is best known for playing the dual roles of Niki Sanders and Tracy Strauss on the NBC science fiction drama Heroes as well as her guest roles on several television shows in the 1990s.Larter's screen debut came in the 1999 film Varsity Blues, followed by the horror films House on Haunted Hill as Sara Wolfe, and Final Destination and Final Destination 2 as Clear Rivers.