Traveling on a train to Waterloo station in London we found the following note tucked down the side of a seat. It was a long train journey and we had nothing more interesting to do, so we set about decoding the message. We just about managed to do this before we arrived - can you?
A G N V T E R
E W T I Y S W
O H M R O N K
E E D E E E A
T T T A E O I
C R L T N T I
Round and round and round we go, Even though our wits are slow, First-Class ticket? How absurd, One should always take a third.
"Round and round" and "take a third" are the clues. You go cyclically through the message taking out every third letter, and get -
NEW YORK DETECTIVES MEETING THE TRAIN AT WATERLOO
We assume that the message's original recipient decoded it, hid the paper and left the train before Waterloo . . . or perhaps not!