The cast for director Nacho Vigalondo’s ambitious new sci-fi project just keeps getting better — in addition to Anne Hathaway, Colossal also stars Tim Blake Nelson and SNL vet Jason Sudeikis, but the latest member of the cast might be the coolest yet: The Guest and former Downton Abbey star Dan Stevens has joined the lineup. Nacho Vigalondo, you had our curiosity, but now you have our attention.

Variety reports that Stevens has been cast in one of two male leading roles opposite Anne Hathaway in Colossal, with Sudeikis playing the other male lead. Tim Blake Nelson and Austin Stowell also star in the film, which is currently in production in Vancouver.

Colossal is a science fiction / romance / monster movie featuring Hathaway as a woman who moves back to her small hometown after she loses her job and endures a devastating breakup in New York. Once she arrives back home, however, she discovers that her mind is psychically linked to a giant monster that’s awoken after years of slumber in Seoul, South Korea. Stevens will play the boyfriend who dumps Hathaway’s character and attempts to win her back.

The film will feature a massive Kaiju-type monster, similar to those seen in the Godzilla franchise and Pacific Rim.

Vigalondo is best known for his ambitious indie films Timecrimes and Open Windows, with Colossal being his biggest project — both in size and vision — yet. Stevens formerly starred on Downtown Abbey before breaking out with his role in the indie throwback thriller The Guest, and appears next opposite Emma Watson in Beauty and the Beast.