The older Dr. Gerald Bull's career as a successful large-bore gun designer takes a turn as he is defunded by the U.S. Army; he then produces weapons for China, Israel, and ultimately South Africa which results in his arrest and conviction for illegal arms dealing.

After his release, Bull promotes his supergun idea to Iraqi dictator Saddam Hussein, and, with funding through BCCI, begins design work on the top secret project, "Babylon".

The end text crawl states that Dr. Bull's murder remains unsolved, and that the U.S. contributed over $3 billion to Iraq in the years preceding the Gulf War.

"[3] The New York Times' review found the film's conceit of a "daunting but lovable" protagonist as a weapons designer to be "loopy", contrasting Bull in real-life as "a difficult man, prickly and quick to take offense" with Langella's portrayal as "endlessly charming.

"[4] The Los Angeles Times review noted no flaws with the film, describing it as an "intricately woven thriller that demands the viewer's undivided attention" and praising Langella's portrayal of Bull.