Benedict Cumberbatch recently attended the South Bank Show Awards, where he let slip he's signed to a fourth series of Sherlock, saying both he and co-star Martin Freeman have "... agreed to two more series but I'm probably going to get into trouble for saying that. All I know at the moment is I'm doing these three and another three."
When asked about the show's future beyond another six episodes, Cumberbatch said "it just depends on Martin and I's availability, how long we can keep it going. It depends on [co-creator] Steven [Moffat]'s ability. I'd love to keep it going. We only do three at a time, so I think the normal fear of over-stretching the mark and just doing too many [doesn't apply]. I'd like to see [Sherlock Holmes] getting older. We're starting quite young. It's rare to see Holmes and Watson at the beginning of their relationship; we usually join them in their mid-to-late 40s or 50s. I've got a way to go. I mean, I'm only 35."
Cumberbatch's words suggest he's open to returning as the modern-day Sherlock Holmes for a great many years to come, if he's keen to see the character into middle-age. Maybe fans should start thinking of Sherlock along the same lines as ITV's Poirot, where David Suchet has kept returning to the role of Hercule Poirot fairly regularly since 1989. Indeed, Suchet's almost filmed all of Agatha Christie's Poirot novels and short stories over this 23-year commitment.
The third series of Sherlock begins filming on 18 March, with a read-through of the first episode having taken place on 12 March. Those three episodes are likely to air in autumn/winter on the BBC, before we most likely face another agonizing wait for a fourth series.