That Demon Within (Mo Ging, traditional Chinese character: 魔警) is a 2014 Hong Kong action psychological thriller film directed by Dante Lam and starring Daniel Wu and Nick Cheung. It premiered at the 64th Berlin International Film Festival in February 2014 and also included on the 16 edition of Far East Film Festival in Udine . The film was released on 18 April 2014.The movie was presented by Dante Lam at the 16 Far East Film Festival 2014 in Udine with The Unbeatable (2013).