Venice film festival: Rooney and Kate Mara play the real-life Chaplin sisters who spoke in unsettling unison in this silly, pointless drama

Sisters Rooney and Kate Mara learned to speak in unison for Werner Herzog's "Bucking Fastard," something that came "surprisingly" easily for them.

Kate and Rooney Mara, who play sisters with a deep and spooky bond in the German's new film, joined the director for a press conference with co-stars Domhnall Gleeson and Orlando…