Joe Otterson TV ReporterChristopher Walken has joined the cast of the upcoming Apple drama series “Severance.”He joins a cast that includes Adam Scott, Patricia Arquette, John Turturro, Tramell Tillman, Jen Tullock, Zach Cherry and Britt Lower. The series is described as a workplace thriller that introduces Lumen Industries, a company that’s looking to take work-life balance to a new level.