Another debut! I like seeing new constructors added to the ever-growing ranks. Neat that each new person brings a different perspective, a different set of inputs that goes into his or her puzzle. So to have two in a week is a treat.
Today's puzzle centers around WHAT'S IN THE BOXES, with six "boxes" all containing four-letter words which can precede "box." (PILLBOX, for example.) A good twist on the "word that can precede or follow" type theme. It's really nice that John kept everything consistent, each of the six "boxes" starting at the top left, reading from left to right and then top to bottom. I got a little tripped up at first because I was expecting them all to run clockwise, but that's likely just me and my preconceived notions of how things ought to be.
John also did a very nice job of choosing his theme answers. I wasn't sure what a SALT box was, but it came easily enough. I looked it up, and it didn't particularly seem like something I really ought to have known (a house style in New England, named after boxes used in the old days to store salt), but it was fun to learn.
There are many four-letter words that can precede BOX, so John did a great job of picking ones that could easily be filled around. Crossing constraints like with these 2x2 boxes are bound to give difficulty, but the only spot of any crunchiness was around the SW corner, with IS NO. The ?SN? pattern is a toughie, to be avoided at all costs — besides ISN'T, there's not much that fills it in a clean way. Otherwise, smooth sailing, excellent work.
The pluralization of the revealer felt a tad off to me, as WHAT'S IN THE BOX feels stronger (a more in-the-language entry related to a kid groveling at cool Uncle Jeff when he brings over a present). Or perhaps if the clue had been related only to the customs officer? Even then, I have a hard time imagining a customs official saying that instead of OPEN THE BOXES RIGHT NOW DAMMIT. Perhaps a inspector at a seaport might be the closest fit in my mind.
Putting that qualm aside, it's a well-executed puzzle. To incorporate 1.) six "boxes," plus 2.) a grid-spanning revealer and 3.) four long pieces of fill is not easy. Many constructors would be fine with the first two components, so I'm glad to see the third piece, which adds a lot of spice to the grid. Excellent job on the layout, especially for his first puzzle.
Really nice debut!