I first saw this 'Brief Encounter' in London two years ago, and then again when the production came to St. Ann's Warehouse in Brooklyn last winter. I always remember it as a delicate, whimsical creation, and worry that it might not thrive in a new environment. Yet it consistently proves sturdier and smarter than I have allowed it to be. And the current incarnation, which arrives courtesy of the Roundabout Theater Company, feels to me richer than ever. It has also been altered, ever so slightly, with the aim of seducing a Broadway audience, which likes to leave a show feeling roused and exhilarated.