In the first film, the comic-foil reins were handled by Xu Da-fu (mainland comedian Huang Bo, also starring in the current comedy hit “Breakup Buddies”), a benign crook whose friendship with Wu was firmly if secretly cemented by the time “The Dawn of Assault” reached its endgame. A little Huang goes a long way, and Xu is back in a happily more limited capacity this time, shouting up a storm with dynamite strapped to his chest before taking a well-earned break for most of the film’s remainder. That leaves Wu and Chen to search for Xu’s imperiled wife, Xiao-qing, whose unborn child is being used to nefarious ends by a fearsome criminal mastermind. Soon our detectives find themselves forced to make some sadistically impossible decisions — like, whether or not to save the innocent hostages who are about to be blown sky-high, when rescuing them might mean the endangerment of countless more lives.