Filmmaker Mikael Hfstrm (Evil, Derailed) discusses his new sci-fi thriller Slingshot and his work with Casey Affleck, Laurence Fishburne, Emily Beecham, and Tomer Kapon. He also revisits his great Stephen King movie, 1408, and shares his thoughts on other King adaptations. Slingshot is out Aug. 30 from Bleecker Street Films.