Best new mystery TV shows for September 2025: Thursday Murder Club, Only Murders In The Building and more

Exciting new mystery series are coming to television, including the star-studded “The Thursday Murder Club” on Netflix (August 28), featuring Helen Mirren and Pierce Brosnan; “Death Valley” on Britbox (September 2), starring Timothy Spall; and “NCIS: Tony & Ziva” on Paramount Plus (September 4), reuniting Michael Weatherly and Cote de Pablo.