In December 2015, Buck was hired to serve as showrunner and executive Producer for the Marvel and Netflix television series Iron Fist. Following the series' debut online via streaming, reviews for Iron Fist were predominantly negative with critics calling it "easily the worst of the Netflix Marvel shows." Despite this, Netflix reported that Iron Fist was their most-binged drama premiere. In December 2016, it was announced that he would return to the Marvel Cinematic Universe as the showrunner and executive Producer for the Marvel, IMAX Corporation, and ABC television series Inhumans. In July 2017, it was announced that Buck was removed from his position as showrunner and executive Producer on the TV series Iron Fist. Inhumans premiered in September 2017 to similarly negative reception.