Explicit in Frontier(s) is its maker's belief that nothing should be left to the imagination. Xavier Gens may pledge allegiance to '70s grindhousers, but like the garbage hauled out at least once a year from Michael Bay's Platinum Dunes production house, or the two-headed, razor-studded dildo formed by Hostel and Hostel II, the style of the French director's career-making torture porn is very much a sign of our times: a capitulation to base pop appetites. The film unspools as a seizure-inducing succession of nonstop screaming, references to horror-film freakouts old and new, and slick market-tested shocks, beginning with a protest rally in the wake of the election of a French right-wing nut and ending with Karina Testa's Last Girl Standing "escaping" from an inn where a deranged posse of cannibalistic neo-Nazis is trying to renew the blood of their family. It sounds enticing, but Gens's engagement with the contemporary racial discord currently tearing at France's bowels isn't sincere but rather a transparent ploy to give the film a sense of gravitas. The director's allusion to the gas chambers of the Holocaust is appropriately tasteless, but Gens seems to resist elaborating on the political subtext he insists upon juicing the story with, using it only to bitch-slap audiences in exactly the same manner as his hysterically herky-jerky, lubed-up aesthetic, which makes Paul Greengrass's Jason Bourne pictures seem like Apichatpong Weerasethakul productions by comparison. At least there's sincerity to the way he acknowledges both his debt to the original Texas Chainsaw Massacre and his pandering to gorehounds, implicit in the sound of squealing pigs perpetually hogging the soundtrack.