Theme:  Unless you’re a super-solver, do read the box that comes with the puzzle.   It’s needed to solve the clues with only dashes inside the land-locked middle square.   The theme is four long across clues (clearly marked) that form a “trivia question” that’s answered in the five circles in the land-locked middle.   Remember that it’s a trivia question and not a riddle.  You’ll likely have to get many of the down clues that cross the acrosses before you can start making educated guesses about the acrosses.   And it’s unlikely you’ll fill in the circles ’til you’ve got a fair amount the acrosses.  To solve the middle section, it’s a good idea to write down the ten starred answers.

I guess that’s more “advice” than  a “hint,” so here goes:  Most of our great grandparents’ (or grandparents’ or parents’, depending on how old you are!) generation ended up putting these in a glass before bed.

Since the theme’s all across clues, all the hints are crossing down clues:

Here’s my only one for a asterisked clue: 15-Down:  Since works is plural you might think the answer ends in “S” or “I.”  It doesn’t.

24-Down Horror director Eli:  Also know for his retirement accounts?

89-Down  Guttural:  You’d think such sounds would come from the gut/diaphragm, but think higher up

93-Down Sort of:   Often used as a prefix

82-Down Literary olios:  What happens when you’re sloppy eating breakfast while reading a book?  Just kidding.  Sounds like a girls name.   (A very common crossword puzzle word (usually in the singular), btw, so commit this one to memory once you get it.)

64-Down Dollar rival:  Think rent-a-car, not money

94-Down Ogling type:  No, not a leerer, but close

86-Down At it:  One word;  Think in a fight, not hard at work.

16-Down French lord:  Oh, so that’s where the French word for “Mister” comes from!

78-Down Mercury and Saturn:  Think of ancient Rome, not cars