Afghan Knights is a 2007 war film/horror film based on an original story by Christine Stringer. The film shows an ex-Navy SEAL called Pepper (Steven Bacic) who suffers with a bad conscience because he has left a comrade behind in Afghanistan and eventually decides to go back in order to try to rescue the man after all. He assembles a bunch of soldiers and goes for it.
In the course of action they come across a mysterious cave system and are confronted by hostile ghosts. This turns the war movie into a horror film.