(FROM THE HOLLYWOOD REPORTER) ? Hilary Duff has joined Winona Ryder, Jon Cryer, Sean Astin, and Chevy Chase in the cast of the Polish brothers comedy Stay Cool. The story is about a successful author (Mark Polish) who faces his unrequited high school crush (Ryder) when he returns home to deliver a commencement address to graduating seniors. Duff plays a high school hottie who asks the author to the prom when he visits her school. Mark and Michael Polish wrote the script and are producing, and Michael is directing. Duff recently shot Safety Glass and Greta, and will be back in the studio to work on her fifth album later this summer. (Hollywood Reporter)