Faintly ridiculous but strangely watchable, director Bruce Burgess’s documentary explores the controversial theory that powered Dan Brown’s pulp juggernaut The Da Vinci Code: that the Catholic Church supposedly covered up Jesus Christ’s child with secret wife Mary Magdalene. While other investigative-nonfiction filmmakers pop blood vessels exaggerating the magnitude of their paltry findings, it’s some relief that Burgess, who serves as Bloodline‘s on-screen narrator, remains doubtful of the “proof” he uncovers, such as buried bottles in France with treasure-map clues leading to embalmed corpses. But considering that he has previously made films about Area 51 and Bigfoot, it’s hard to take his role as a skeptic that seriously—more likely, he just enjoys milking an audience’s conspiracy-theory fascination without having to worry about producing meaningful results. Despite the fact that several people who claimed to possess evidence about the cover-up have died under mysterious circumstances, Bloodline is less a gripping exposé than a goofy National Treasure–style puzzle film mixed with a sub–Nick Broomfield survey of some admittedly oddball individuals. But when Burgess tries to craft an ambiguous, even ominous ending out of his inconclusive study, it seems painfully ironic that a film questioning other people’s faith would ask us to take a documentary this slipshod at its word.