Watch Katherine Heigl Play a Seriously Crazy Ex-Wife in First Trailer of Unforgettable

It's not always easy moving on. Katherine Heigl is taking on the role of a jealous ex-wife out for revenge in her upcoming film Unforgettable -- and PEOPLE has the exclusive worldwide debut of the trailer. In it, Tessa (Heigl) struggles to accept her ex-husband David's new wife Julia (Rosario Dawson). "You know, there was a time when I thought we were on the road to getting back together, but then he met you," Heigl's character says. And as she watches Julia bond with her daughter and grow even ...