Some movies can encapsulate an entire situation using just two players, and some can’t. Following the ensemble-cast approach of Syriana and The Good Shepherd, the tightly focused Breach zooms in on a pair of real-life characters: treasonous FBI agent Robert Hanssen, busted in 2001 for what one character calls “the worst breach in the history of U.S. intelligence,” and Eric O’Neill, the young agent-in-training who escorted Hanssen to his downfall. If the movie seems a little smaller than the events it recounts, it looks gigantic next to Factory Girl, in which the corrupt elder is Andy Warhol and the acolyte is Edie Sedgwick. The latter film is also rooted in fact, but it sacrifices plausibility for a glib analysis of its pivotal relationship.

Breach was scripted by its director, Billy Ray, although officially he shares credit with Adam Mazer and William Rotko, who wrote an earlier version. The movie begins at the end, with then Attorney General John Ashcroft announcing Hanssen’s arrest, then rewinds just a little. It’s two months earlier, and O’Neill (Ryan Phillippe) is working a stakeout while Hanssen (Chris Cooper) leaves a downtown church. The apprentice and the veteran are about to meet, coming from opposite directions. O’Neill is recruited by Agent Burroughs (Laura Linney) to be Hanssen’s new assistant, with the covert purpose of exposing him. But as what? At first, O’Neill is told only that Hanssen is a “sexual deviant.”

That’s the least of it, although O’Neill has trouble getting a read on his subject. Hanssen and his pious wife, Bonnie (Kathleen Quinlan), barge into the younger man’s life, trying to bolster his Catholicism and enlist his wife, Juliana (Caroline Dhavernas), a German woman of no strong religious interests. Although Hanssen is arrogant, brusque, and sometimes overwhelming, O’Neill doesn’t see him as any sort of criminal. When he says as much to Burroughs, she finally explains that Hanssen began spying for the Soviet Union more than 20 years earlier. The rest of the movie is heavily procedural, as O’Neill keeps Hanssen occupied while hundreds of FBI agents finalize the case against him.

Ray’s only previous film as a director, Shattered Glass, observed a power struggle (also derived from real events) between a callow, duplicitous New Republic writer and his sympathetic but responsible editor. Breach flips the scenario by making the older guy the deceiver, but otherwise the films are quite similar. Rather than attempt to go spelunking deep into Hanssen’s character, Ray concentrates on his behavior. (As the renegade agent finally asks, “The why doesn’t mean a thing, does it?”) The movie shows how Hanssen deployed his own aggressiveness and unpredictability, keeping superiors and subordinates alike perpetually off balance. The key to this depiction is Cooper, a masterly actor who vanishes into his characters without relying on gimmicks. He makes the incongruities of Hanssen—who could shift from extolling Opus Dei to proffering a sex tape featuring his wife—utterly believable.

O’Neill and Hanssen’s intense relationship is a sort of perverse romance—each man is trying to seduce the other for his own (or the FBI’s) purposes. Interlaced with this is the fraying of O’Neill’s marriage, which plays as less plausible. The FBI trainee is instructed to tell Juliana nothing about the case, but surely O’Neill would have been more reassuring to his wife than his fictionalized counterpart manages to be.

If Cooper’s Hanssen is a force of nature, that’s the only one in Breach. Ray takes an approach that might be termed European (or simply low-budget), holding much of the action off-screen and ignoring the aspects of the story that could have made for a livelier, more traditional spy flick. (That Hanssen himself was once assigned to find the Soviets’ mole—that is, himself—is mentioned only in passing.) There are a few suspenseful sequences, but they lead not to punch-outs but to verbal battles of will between the two central characters.

In one unlikely moment, Hanssen is shown firing off a few shots in Rock Creek Park, but that’s just for show. Much like Shattered Glass, Breach is about men who brawl with words, not weapons. That’s just how life is for most spies. And, of course, most screenwriters.