Swiss playwright-novelist Friedrich Durrenmatt and American actor-director Sean Penn aren't exactly this year's fun couple. Durrenmatt poses moral conundrums and expects his protagonists to work them out while we watch; Penn is the most internal of actors, and as a director he is unconcerned with any kind of show-and-tell work, preferring to let us find psychological rather than moral truth in his films.
Penn and his screenwriters have recast "The Pledge" into the story of a lonely, sixtyish bachelor police detective in a rural county near Reno, whose retirement party is interrupted by the discovery of the body of a little girl who's been raped and murdered. Jack Nicholson is the detective, and he too is a misfit here, because as an actor he is all exteriors. Though he does everything Penn directs him to do, we in the audience only see what he shows us, rather than what is inside him.
In any case, his character is like the old horse who can't stand being put out to pasture. He can't let the case go, and on his own begins to investigate commonalities with other murders of little girls. At the same time, officially retired, he buys an old gas station with living quarters above, and takes in a battered single mother and her own little girl.
Though the police seem to have solved the crime with the arrest of a slow-witted Indian (Benicio Del Toro in an over-the-top performance that belongs more in an actors' improv class than a murder mystery), Nicholson soldiers on, and finally locates the likely murder suspect. Here the film goes even darker, because Nicholson wants to use the little girl as bait for the killer, having arranged for a task force of police to wait for his arrival. Unfortunately for the film, the climax and resolution are mechanical and shallow, and what power it had during the search is vitiated by the film's quick rush to end things.
Nicholson does his best, but he is sadly miscast here, using gesture instead of emotion to make his mark. On the other hand, Robin Wright Penn as the mother who moves in with him is excellent, as are a number of well-known actors in tiny roles along the way, including Vanessa Redgrave, Mickey Rourke, Sam Shepard, Helen Mirren, and Harry Dean Stanton; but all their good work is done in a losing cause.