Charming buffoon or cunning chameleon? Welcoming liberal or snarling Brexiteer? We ask why, despite having no guiding philosophy, Boris Johnson is so likely to become Britain’s prime minister. Our obituaries editor remembers the socialite Claus von Bülow, his sensational attempted-murder trials in America and the enduring question of whether he did it. And, despite appearances, China’s and America’s film markets are growing further apart.