I just finished this week’s Listener puzzle, “Vive le Différence” by Kevin. Well, I have the grid filled in, which is all I need to enter the competition. But I don’t really understand it. According to the instructions, “the resulting grid symbolically marks a milestone on a journey begun on March 23, 1991, as calculated from a slightly earlier departure”. I see what is formed by the replaced letters, but I don’t know what the journey is or what the milestone is or what is meant by the slightly earlier departure.

Later: Ah, just figured out what the milestone is and all the rest. Nice.