“Game of Thrones” actor James Cosmo has joined military drama “Tomorrow.” The film is exec produced by Martin Scorsese in his first venture into British filmmaking.

Previously announced cast includes Stephen Fry, Stephanie Leonidas, Sebastian Street, Stuart Brennan, Sophie Kennedy ­Clark, Paul Kaye and Joss Stone.

Scorsese’s longtime script supervisor Martha Pinson is making her feature directorial debut on “Tomorrow.”

The script is written by Brennan and Street, who are producing alongside Dean M. Woodford. Emma Tillinger Koskoff is executive producing with Scorsese. Production companies are Roaring Mouse Productions and Studio 82.

The story explores the difficulty and loneliness soldiers encounter as they try to reintegrate into society having after serving their countries and deals with post-­traumatic stress disorder, HIV and AIDS.

The production, which is launching near the end of the U.K. combat mission in Afghanistan when British troops will be withdrawing after 13 years of fighting, is supporting the Help for Heroes charity.

Carnaby International will be selling international rights at the upcoming American Film Market.