The show from 'Downton Abbey' producer Carnival Films has become U.K. network Sky 1's most successful original drama series. Stan Lee's first foray into British television has been a successful one. The 10-part first season, which concludes on Friday, is the channel's highest-rated original drama of all time, with an average audience of 1.9 million, and is also the most-watched Sky 1 program on its online streaming service Now TV.