The mysteriously titled Seven Pounds stars Will Smith as Ben Thomas, who flashes his badge as an IRS agent to gain entrance into the lives of seven strangers in need. To each, he offers something that will reverse their troubles, seeking to atone for a haunting past mistake. But when Ben starts falling in love with a young woman with heart trouble (Rosario Dawson), his carefully laid plans threaten to collapse. To reveal more of the story would diminish it. Smith is an engaging, charismatic presence, butthe impact of Seven Pounds comes from Dawson--she has the kind of emotional transparency that shimmers off the screen. Which is crucial, because Seven Pounds requires considerable suspension of disbelief; some scenes push and pull at plausibility, and youmay question a few plot turns after the movie is over. But as the story unfolds, the performances can carry you over these bumps. If you surrender to its gently circling rhythms and its luminous images (including the glowing undulations of a poisonous jellyfish), Seven Pounds will pack an emotional wallop, heartbreaking and uplifting at the same time.