"We've agreed to two more [seasons,] but I could get into trouble for saying that," Cumberbatch told Radio Times.
"All I know at the moment is we're doing these three [TV movie-length episodes for Season 3] and another three. I just don't know what there is beyond that. ... It just depends on Martin and [my] availability, how long we can keep it going. It depends on Steven's ability. I'd love to keep it going."