from Laura Linney (as Penn's wife) and Marcia Gay Harden. Kevin Bacon is saddled with a romantic subplot that we don't care sufficiently about, but he, too, is mesmerising.
And the best scenes in the movie are between him and Fishburne, who bicker yet understand each other like a couple who really have worked together for years.
Tim Robbins gives his most powerful and complex performance yet, managing to be just together enough to make us accept him as a husband and father, but sufficiently damaged for us to believe the horror of a childhood trauma which keeps returning to haunt him.
Sean Penn is brilliant towards the end, when he unselfishly allows other actors - first Robbins, then Linney and Bacon - room to act.
Early on, however, he works a little too hard, overdoing the Method acting, indulging in so many facial contortions that - for me, at least - he overstepped the line between Great Acting and Incurable Ham.
The raw intensity of his emotion when he discovers his daughter is dead is hard to watch, and I don't mean that entirely as a compliment.
My suspicion is that Penn will be the actor who wins an Oscar nomination, for he is all too clearly acting, and he probably deserved to triumph a few years back for Dead Man Walking. But Penn does go over the top and Eastwood indulges him, with fatal consequences for the film's pace and balance.
A lot of people will think the film drags, although it sustained my interest all the way to the end. Mystic River is a fine, deep thriller that deserves to be a favourite with thinking audiences for its complexity and the director's superb professionalism.
Clint creates a real sense of a blue-collar community, shows a fine eye for social detail, and also contributes an atmospheric score.
Whether he's made a hit movie is another matter - but perhaps he's old, rich and wise enough not to care.
