Directed by Jacques Rivette (one of the big beasts of the French Nouvelle Vague) Secret Defense is best understood as a sort of inside-out psychological thriller. What I mean by this is that while most psychological thrillers use the language of film to convey what it feels like to be in a particular psychological state, Rivette’s film looks beyond what the characters are feeling and focuses instead upon the insane realities of what it is they are doing.

The film opens as research scientist Sylvie (Sandrine Bonnaire) is approached by her younger brother Paul (Gregoire Colin). Obviously troubled, Paul presents Sylvie with photographic evidence suggesting that the charismatic and ambitious Walser (Jerzy Radziwilowicz) might have been involved in the death of their powerful father. Initially dismissive of her brother’s conspiracy theories, Sylvie soon becomes worried that Paul might be planning to do something stupid and so decides to ‘save’ her brother by travelling across the country in order to kill Walser herself.

At this, point, most directors would have used either the relationship between the siblings or their historic links to Walser as a means of exploring Sylvie’s character and explaining her decision to seek revenge on her brother’s behalf. However, rather than following this well-trodden path, Rivette devotes twenty minutes of the film to a largely dialogue-free train journey during which Sylvie sleeps, tries on sunglasses, changes trains and gets drunk. The sheer crushing boredom of this section beautifully demonstrates the depths of Sylvie’s madness and obsession whilst keeping her actual emotional state firmly at arm’s length. Indeed, the reason Secret Defense runs to a colossal 170 minutes is that each of the film’s revelations comes only after a succession of missed phone-calls, awkwardly silent breakfasts, gloomy afternoons spent sitting around, and seductions embarked upon solely to give the characters an excuse to not talk to each other. In fact, this cycle of avoidance, confrontation and acceptance repeats itself endlessly throughout the film but without much insight ever being gained.

The point of the film is that it takes considerable time and energy to both keep and reveal family secrets. Much like the intelligence services alluded to by the film’s title, Sylvie works hard to break through a wall of silence and once that wall is finally breached she pointedly refuses to reveal the family’s secret to her troubled younger brother. There’s simply too much at stake and he wouldn’t understand anyway.

By focussing upon the characters’ actions rather than their exact motivations, Rivette emphasises not only the irrationality of the characters’ actions but also the social nature of many psychological states. When Walser finally lets Sylvie in on the family secret, Sylvie lashes out at her mother and then immediately forgives her; it is as though she has passed through a veil from one world into another where secrecy and even murder make perfect sense. Thus, the decision to keep the characters at arms’ length results in a truly devastating psychological truth: all human behaviour seems irrational and insane when deprived of its cultural and psychological context.