I finished this Friday’s Listener crossword, “Ballad” by Elgin, late Saturday morning after a longer struggle than usual.

It’s a tough puzzle. The across clues aren’t given entry numbers for the grid, and they are listed not in order of their appearance but in the alphabetical order of their answers. Now, this actually helps a lot in solving them: You can figure that a clue, say, about a third of the way down in the list probably starts with a letter around F or G or H. Then as you find some of the answers, that helps narrow down the possibilities for the rest; if one answer is GENERAL and the answer two clues down is GOLDFISH, then you know that the answer to the clue between them starts with a G and the second letter is somewhere between E and O, which probably means GE, GH, GI, GL, GN, or GO. So even without any help from crossing letters, the possibilities for the across clues narrow pretty rapidly, and it wasn’t all that long before I had close to half of them solved.

However, you could solve all the across answers and still not know where to put any of them in the grid. For that, you need help from some down clues. Down clues are ordered normally, so once you solve one you know exactly where in the grid to place it. But you don’t get any help from crossing letters till you’ve placed a few of the across answers, and you can’t place any of the across answers till you’ve solved some of the down answers, so you have to solve at least a handful of the down clues without any help from crossing letters before you can start filling in any of the grid.

But on top of that, the across answers may be entered either left to right or right to left, and there are no vertical bars to show where across entries begin and end, so that has to be deduced as you go along, and there are additional strange things in the instructions about a missing column in the grid and two across answers that have to be entered overlapping and some unknown number of across answers that aren’t entered in the grid at all, and these things also have to be figured out as you go along.

And on top of that, the clues are a lot harder than usual, though inventive and fair, I’d say. So all in all I found filling the grid to be a slo-o-o-o-ow, gradual process.

I didn’t figure out what the theme of the puzzle was until I’d just about finished filling the grid. But it’s a delightful surprise to discover the theme and see how it is worked into the puzzle in several amusing ways, justifying all the odd things about the puzzle. Everything comes together very satisfyingly. All in all, a tough puzzle, but worth the struggle.

There are a few clues where I know from the completed grid that I must have the right answer but I still don’t understand the wordplay. For another clue, I think I understand the wordplay but the clue seems to involve an alternative spelling that, while perfectly familiar to me, is nevertheless not given in Chambers Dictionary, or at least in the iPhone version (the only version that I have the latest edition in). That seems like it shouldn’t be kosher according to the rules of the Listener puzzle, but I’m not really sure.