Cannes: The "Train to Busan" director is as technically proficient at action sequences as ever, but its metaphors for AI and authoritarianism don't hit as hard as genre fans need them to right now. A throwaway line early in “ Colony ,” Yeon Sang-ho ’s latest follow-up to his 2016 monster hit “Train to Busan,” between an underdog brother-sister pair of characters, suggests that leaving his job as a mall security guard and the grind of her wheelchair-bound life as an IT employee to go camping