EXCLUSIVE: Toby Stephens, who next year will reprise his role as Captain Flint in Starz’s fourth and final season of Black Sails, will star opposite Gerard Butler in Millennium’s action thriller Hunter Killer. The story revolves around an American submarine commander (Butler) sent into Russian waters to save the Russian President in the midst of a military coup. Stephens will play Lt. Beaman, who heads up the black ops squad.

The screenplay is written by Peter Craig and Jamie Moss and is based on the novel Firing Point by George Wallace and Don Keith. The film is produced by Original Film’s Neal Moritz and Toby Jaffe, Butler, Alan Siegel, Tucker Tooley, Mark Gill, John Thompson and Matt O’Toole. The executive producers are Douglas Urbanski, Avi Lerner, Trevor Short, Les Weldon, Boaz Davidson and Christine Otal. Relativity’s Dana Brunetti and Ryan Kavanaugh are also said to be getting exec producer credits.

Stephens was recently seen in 13 Hours opposite John Krasinski but he is probably best known for his role on Black Sails, the critically acclaimed series which is the first on Starz to go beyond three seasons.

Stephens is repped by Olivia Homan at United Agents in the UK.