The vampiric need for blood to survive is replaced with human flesh and body parts in "We Are What We Are," a cannibalism drama written and directed by Mexican filmmaker Jorge Michel Grau. The idea isn't half-bad, taking a tried-and-true conflict of the genre and adding a twist to it, yet Grau almost seems shy at exploring the subject head-on. It's one thing to keep certain aspects of a story close to the vest, or even to purposely leave room for ambiguity, but "We Are What We Are" time and again promises answers and payoffs that do not come. Instead of being enigmatic for a reason, the film feels simply half-formed.

The first scene, in which a dazed older man (Humberto Yánez) in physical distress collapses at an outdoor mall and is then carried off, his blackened vomit promptly mopped up by the cleaning crew as if the event never happened, is a stirring start. When word of his death arrives, his family—stern, pessimistic wife Patricia (Carmen Beato), sons Alfredo (Francisco Barreiro) and Julian (the late Alan Chávez, tragically killed in 2009 at the age of 19), and daughter Sabina (Pauline Gaitan)—are suddenly faced without a patriarchal figure to bring back their human meals. Level-headed eldest son Alfredo finally takes the reigns, but he's ill-equipped in providing for loved ones who desperately need a sacrifice soon or risk facing the same sad fate as his father.

The desperate, downtrodden family at the center of "We Are What We Are" provocatively stand as a pointed metaphor for the way poverty and socioeconomic stress are too often swept under the rug, but this thematically timely topic is all the finished picture has going for it. Mostly, the movie is just riddled with questions. What is the purpose of the all-important ritual they hope to carry out the following day? Why do they need to eat people (consistently shown off-screen) to live? Are they human at all? How do they know they are less than twenty-four hours from dying if they are still so healthy-looking and able-bodied? With the characters never growing beyond two dimensions meant to forward the narrative, the viewer is left dissatisfied and wanting by a script that isn't interested in digging beneath the surface.