A towel, the Hitchhikers Guide to the Galaxy says, is about the most massively useful thing an interstellar hitchhiker can have.
Most years I forget towel day until I see someone post about it, but this year I’ve been more organised and made a little (kind of big) back-of-the-cereal-box style puzzle to celebrate.
See if you can find out who stole Arthur’s towel.
(the print friendly version is on the second slide or you can download it below)