In the 2005 movie Brokeback Mountain, Heath Ledger fell in love with a ranch hand played by Jake Gyllenhaal, but offscreen, he found romance with another costar: Michelle Williams, who played his unhappy wife. The Dawson's Creek alumna, 27, and her Aussie beau, 28, both emerged from the experience with Oscar nominations—and even more happily, a daughter, Matilda, now 23 months old. As the young parents set up house in a Brooklyn brownstone, they kept the public guessing about their marital status. "We try not to talk about it ... it's obviously very sacred," Ledger told Newsweek in April. But a few weeks ago, the two quietly called their coupledom off. The split was amicable, says a source close to Ledger and Williams: "It was rocky for a while and they did what they could to make it work."

Ledger "is down, he's bummed about the breakup," says another source. While Williams has stayed near home with Matilda lately, Ledger spent much of the summer filming his role as the Joker in the Batman Begins sequel The Dark Knight. Then he headed to the Venice Film Festival to promote the Bob Dylan bio I'm Not There, in which Williams also appears, though the two share no scenes. "He's working," says a source in Venice, "and he's getting on with it."

  • Contributors:
  • Reported by Courtney Rubin/Venice,
  • Jeffrey Slonim/New York.