Acclaimed director Ron Howard’s Rush isn’t in theaters yet, but with the film completed his eyes are already turned to his next project. In the Heart of the Sea is based on Nathaniel Philbrick’s book of the same name which recounts the ventures of the whaling ship Essex in 1820. The ship was stalked and attacked by a sperm whale which eventually wrecked the ship and left the surviving crew adrift in a lifeboat where they were stranded for 90 days before rescue. Herman Mellville interviewed survivors of the Essex while researching for Moby Dick, and it seems likely Melville will appear in the film, his interviews providing something of a framing device for the story.

Chris Hemsworth had already signed on to another voyage with Howard (he co-stars with Daniel Bruhl in Rush), as had Cillian Murphy (Inception, Batman Begins), Benjamin Walker (Abraham Lincoln: Vampire Hunter), and Tom Holland (The Impossible), but the cast has grown by two with news that Brendan Gleeson and Sam Keeley have also come aboard. Gleeson recently completed roles in The Smurfs 2 (out July 31) and Robert Redford’s The Company You Keep, and is also well-known for his role as Mad-Eye Moody in the Harry Potter films. Variety is reporting that Gleeson will play an older version of one of the survivors whom Mellville interviews. If we were betting, we’d say this is the elder Owen Chase. Hemsworth plays the younger Chase, the Essex‘s first mate. Tom Holland’s Thomas Nickerson, cabin boy on the Essex, would make sense as well. As for Sam Keely, best known for his role in the Sean Penn-starrer There Must Be a Place, he’ll be an Essex crewman, although his exact role has not yet been specified.

In the Heart of the Sea is currently in pre-production and will begin shooting in September.