Can Christopher Nolan's 'Dunkirk' rake it in at the box offices?

What are the highlights from Comic Con? We also get reviews of “Dunkirk,” about an epic battle and troop evacuation in World War II; “Valerian and the City of a Thousand Planets,” a sci-fi thriller in which 1000 planets are threatened by a dark force; and “Landline,” an indie about a family in Manhattan.