It ’ s been an agonizing nine-year wait for writer-director Sean Durkin to follow up his outstanding 2011 debut Martha Marcy May Marlene , but he ’ s finally gotten the finger out and delivered a second feature . And boy , has he delivered ! Returning to the UK , where he was raised as a child and where he directed the 2013 Channel 4 mini-series Southcliffe , Durkin has given us a doom-laden rejoinder