About two months after the rumors of Benedict Cumberpatch’s (12 Years a Slave, Star Trek Into Darkness) involvement with the project, The Lost City of Z looks to boost its star power by adding another cast member. Robert Pattinson (The Twilight Saga, Cosmopolis) will join Cumberpatch in the story of English soldier and explorer Colonel Percy Harrison Fawcett.

Cumberpatch will star as Fawcett, whose belief in the existence of a secret city in South America led him on many journeys into the Amazon. While Pattinson’s role in the film is not yet clear, there is speculation that he will most likely play the role of Fawcett’s son. In 1925 Fawcett and his son Jack embarked on one final adventure in search of the city. Neither was heard from again.

The film is based on the 2009 book The Lost City of Z: A Tale of Deadly Obsession in the Amazon. Author David Grann presents evidence as to what may have happened to the Fawcetts and where the city is located.

James Gray (The Yards, We Own The Night) will direct The Lost City of Z, while Brad Pitt’s Plan B Entertainment will produce.