It might very well require the services of Sherlock Holmes.
While visiting London in early November, EastEnders enthusiast and New Yorker Cary Portway stumbled upon a poster on a street lamp dubbed 'Rotten Cotton', adorned with a photo of Albert Square icons, son and mum Dot and 'Nasty Nick' Cotton.
The poster adopts the title and lettering of the classic punk rock album by the Sex Pistols, Never Mind the Bollocks, and then asks provocatively, "Who's Behind The ... Rotten Cotton." That's a very good question, indeed!
"We were in Carnaby Street to see the Rolling Stones Christmas decorations (did you ever think there would be such a thing?!)," Portway explains. "And that's the only place in all of London (and I was everywhere!) that I saw them. Let me know if you ever find out what it's all about."
Combing the Web to solve the mystery of its existence, we came up empty-handed, other than the surely dumbfounded California-based, heavy-metal band t-shirt company (www.rottencotton.com), which apparently doesn't have any EastEnders connections; they didn't respond to our enquiring email.
The Walford Gazette then checked with Jim Vogiatzis, personal assistant to June Brown (Dot), who reports: "I have not been able to find out anything about the poster ... just as much a mystery to us."
And it was the first time that John Altman (Nick) had seen it, too. "I have no idea what that poster is about. Do let me know if you find out. All the best, John," writes Altman, in an email between rehearsals for the panto, Aladdin, in which he plays 'Abanazar' at Stockport Plaza from 7 December 2012 to 6 January 2013.
Follow Larry Jaffee on Twitter: www.twitter.com/lsjaffee