Robert Eggers drops a second 'Werwulf' trailer plus a full-moon online scavenger hunt. He says it's the darkest thing he has ever written.

The trailer is only the first bite. IndieWire reports that Robert Eggers, the director behind "The Witch," "The Lighthouse," "The Northman" and "Nosferatu," has released a second trailer for "Werwulf," his werewolf film set in a 13th-century English village, and paired it with an online game. Aaron Taylor-Johnson stars as a man who transforms into a werewolf each full moon, with Eggers regulars including Willem Dafoe in the ensemble. Focus Features is keeping the plot under wraps, offering only an official synopsis: "Focus Features presents 'Werwulf,' a harrowing tale of devotion, damnation, and the devil within." The game goes live on the full moon for each of the next three months, starting with today's Harvest Moon. Each full moon launches a 24-hour online scavenger hunt in which fans search the film's digital platforms for a hidden code and enter it before time runs out, with sign-ups at the appropriately titled DevourethAllMankynde.com. At a conversation on the Universal lot moderated by Focus chairman Peter Kujawski, Eggers said that after "Nosferatu" he told himself, "Let me try to write the scariest thing I can write." Then he added, "I don't know that I did that, but I definitely wrote the darkest thing." He wrote the script with frequent collaborator Sjón. "Werwulf" opens in theaters Friday, Dec. 25. Here is the lesson. A trailer and a scavenger hunt are marketing, and smart marketing at that, because they ask an audience to lean in instead of scroll past. The real test comes on Christmas Day, when a filmmaker who takes old folk tales seriously asks audiences to spend a holiday night with something truly dark. Parents, read up before you bring the kids. Grown-ups who want more serious craft at the multiplex, that ticket still counts as a vote.