Dylan McDermott (American Horror Story) is the newest addition to Mercy, the upcoming film based on Stephen King's short story "Gramma."
Mercy is poised to be a genre powerhouse. In addition to being based on a Stephen King story, it was adapted for the screen by Matt Greenberg (Halloween: H20, 1408). Peter Cornwell (The Haunting in Connecticut) is directing, and Jason Blum's Blumhouse Productions (who also gave us Sinister and Insidious) is producing. Chandler Riggs (The Walking Dead), Joel Courtney (Super 8) and Frances O'Connor (A.I.: Artificial Intelligence) star.
The film follows two young brothers (Riggs and Courtney) who go with their mom (O'Connor) to care for their grandmother. Unbenknownst to the younger generation, granny has been deeply invested in black magic for many years. McDermott plays an old fling who still yearns for his lost love, despite being married to someone else.
Source: Hollywood Reporter