'' 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
64th Berlin International Film Festival
64th Berlin International Film Festival
That Demon Within