Which 10-letter word connects a Jubilee line commute and Stanmore's Second World War heritage? Answer: crosswords.
These black and white brainteasers lie at the centre of a new project that forms part of Transport for London's Art on the Underground programme.
The idea is that commuters pick up a puzzle book from Jubilee line stations, crack the clues and check the correct answers at Stanmore station, where they have been incorporated into new artwork.
Stanmore's wartime secret was that it was home to an undisclosed outstation for some of the codebreaking machines used at Bletchley Park, near Milton Keynes, Buckinghamshire, to decipher the German enigma code.
Codebreaking recruits were required to complete the fiendish Daily Telegraph crossword in 12 minutes - about the same time it takes to get from Wembley Park to Stanmore.
So, with a pen in one hand and TfL's crossword booklet in the other, I took up the challenge to solve the cryptic puzzles and find their solutions contained with the beautifully striking station artwork by Dollis Hill artist Serena Korda.
The themed puzzles feature local organisations such as Stanmore Choral Society, the Royal National Orthopedic Hospital, Stanmore Bowls Club and Bletchley Park, which serve to commemorate Stanmore's Second World War links.
I began my journey at Wembley Park and started on the first crossword. I soon realised, however, the high calibre of the Bletchley Park codebreaker recruits - and that I was a relative crossword dunce.
After 12 minutes of chewing my pen and taxing the old grey matter, I arrived at Stanmore, where I was met by Korda's playful artwork.
Her linocut designs grace the platform and stairwell and provided (for me), much-needed hints at the solutions. At the top of the stairs are the completed crosswords in heraldic form on the walls and ceilings of the entrance hall.
The art surrounding the crosswords has intricate designs, almost regal in their appearance, and the wartime themed art creates a nostalgic effect.
In the production of the final work, Korda collaborated with crossword setters Geoff Heath and Roy Dean and the self-titled Stanmore Puzzlers.
Korda, 29, who went to school in Stanmore, tells me : "It is nice to to have a personal connection with the area and extend it beyond my own previous routine by bringing people together who share similar interests.
"I have been told by the station supervisor that customers have been responding well to the project.
"It is nice that people have been interacting with the leaflets and that there is more to see than just the crossword solutions."
'The Answer at the End of the Line' project has been running since July 1 and will now become a permanent feature of Stanmore.
[25a0] The crossword booklets can also be downloaded from: www.tfl.gov.uk/tfl/ corporate/projectsandschemes/ artmusicdesign/pfa/events/serenakorda.asp.