An army of Sherlock Holmes fans have donned their deerstalkers and picked up their pipes in an attempt to break an unusual Guinness World Record to mark TV star Benedict Cumberbatch's birthday.
Dressed as the enigmatic detective, the group of 113 people recorded a message for their favourite Holmes actor, who turned 38 today.
But first the group, including children, showed off their crime-fighting attire outside University College London.
Strict rules dictated that they also had to be wearing a cape and holding a magnifying glass to qualify for the record attempt, which is being considered by judges.
The event was organised by the Undershaw Preservation Society which is working to preserve the former home of the book's author, Sir Arthur Conan Doyle.
While the BBC recently revived the world-famous detective stories, Undershaw in Hindhead, Surrey, where they were written, remains in a neglected state.
A spokesman for the Undershaw Preservation Society - which has the support of actor Stephen Fry and Mark Gatiss, co-producer of the BBC series Sherlock - said it was a "brilliant day".
"We are all massive Benedict fans so we're hoping that he spots our birthday message for him and hears about what we're doing," he said.
"Everybody in the Sherlock community recognises that Conan Doyle is the father of modern crime fiction so it's an important project."
Undershaw is to be refurbished into a school for children with disabilities next year, but the study where Conan Doyle wrote is to be returned to its original Victorian state by the society and opened to the public.