It’s a bit ironic that one of the most original filmmakers of our time has made one of his very best films by following someone else’s formula. A remake of the Hong Kong film Infernal Affairs, Martin Scorsese’s The Departed (A) traces a young undercover cop (Leonardo DiCaprio) infiltrating a South Boston crime syndicate led by Jack Nicolson while the mobster’s protégé (Matt Damon) has simultaneously penetrated the police department as an informer for the syndicate. Both DiCaprio and Damon become deeply consumed by their double lives and the plans and counter-plans of their respective operations; but when they discover there’s a mole in their midst, they must race to expose each other’s identity. This is Scorsese at his most efficient, with each and every sequence important to the plot and every shot of blink-and-you-missed-it importance to the big picture. It’s an astonishing adventure with a great trio of central performances plus many other great ones in the ensemble including Mark Wahlberg, Alec Baldwin, Martin Sheen and Vera Farmiga.