A trailer for a Christmas special for the BBC series Sherlock has been released and there's a twist in the tail for the one-off episode: it's set in the 19th century.
The trailer shows Benedict Cumberbatch's Sherlock and Martin Freeman's Watson solving mysteries in the same time period as Sir Arthur Conan Doyle's original works.
The pair race around the cobbled streets of London, illuminated by lantern or candlelight and everyone look appropriately old-timey with their top hats and elaborate mustaches.
None of the sly wit the show is known for is lost with the change of setting, however, with the teaser closing with Watson irritably insisting Sherlock wear his trademark deerstalker as they leave 221B Baker St.
"You're Sherlock Holmes," he says. "Wear the damn hat."
