Crossroads Films has attached Sam Rockwell and Amanda Peet to the David Gordon Green-penned "Snow Angels." Meanwhile, Emily Mortimer has an offer for a role. Adapted from the novel by Stewart O'Nan, the story interweaves the life of a teenager, Arthur, with his one-time baby sitter Annie (Mortimer), who is struggling with a young daughter and her estranged husband, Glenn (Rockwell). Peet plays Barb, the female lead. Jesse Peretz ("The Chateau") directs. "I am so excited to have the chance to work with David and this incredibly talented cast on a project I have been passionate about for a long time," Peretz said. The project is being produced by Crossroads principals Dan Lindau and Camille Taylor along with Paul Miller. Rockwell's credits include "Confessions of a Dangerous Mind" and "Matchstick Men." Mortimer's include "Dear Frankie" and "Bright Young Things." Peet currently can be seen in "Melinda and Melinda." Her upcoming projects include "A Lot Like Love." Rockwell and Peet are repped by the Gersh Agency, and Mortimer is repped by WMA. Cinetic Media will oversee financing and sales.