James Earl Jones and his first film.

Amazingly, it was Dr. Strangelove. He reminisces about the film, its original story source, and working with Kubrick.

Kubrick based his initial script on "Red Alert," a tense thriller about the possibility of an accidental nuclear war written by the British author Peter George.... As the script evolved, Kubrick decided to bring in the renowned "bad boy" Terry Southern to rework the film as a satire. Among many other changes, an entirely new character was added to the story--the eponymous Dr. Strangelove (initially called Von Klutz).