The I Know What You Did Last Summer legacy sequel took some shocking twists and turns, some of which even surprised star Madelyn Cline. Warning: spoilers ahead! Cline, 27, opened up about the surprising return of Sarah Michelle Gellar's Helen Shivers and how the cameo required her to come back to set to film more scenes. "I only got the news that I was coming back about two and a half weeks ago. We shot all those very, very end scenes about two weeks ago," Cline told The Hollywood Reporter in an interview published on Monday, July 21.