The Tom Hanks-produced John F. Kennedy assassination film Parkland is cobbling together a formidable cast. Zac Efron and Marcia Gay Harden are the latest to come aboard, joining Paul Giamatti, Billy Bob Thornton, and Jacki Weaver. Based on Vincent Bugliosi’s 1,600-pager Reclaiming History: The Assassination Of President John F. Kennedy, the film will take place at Dallas's Parkland Hospital on the day of Kennedy's murder. Nice timing, with Jonathan Demme's adaptation of Stephen King's 11/22/63 recently falling apart. One JFK thing at a time, people.