puzzle box

Noun

puzzle box (plural puzzle boxes)

1. A box that cannot be opened by the usual obvious means, and therefore challenges a person to find the correct way to open it.
   • "Jest like the Injian puzzle-boxes, ain't they?" said Dan, as the one boat dropped into the other.1896 November – 1897 May, Rudyard Kipling, “Captains Courageous”, Garden City, N.Y.: Doubleday & Company, published 1897, →OCLC
   • They walked about this town and found their own house, just as before, and went in, and there was the toy town on the floor; and you will see that they might have walked into that town also, but they saw that it was no good, and that they couldn’t get out that way, but would only get deeper and...1901, E. Nesbit, “The Town in the Library, in the Town in the Library”, in Nine Unlikely Tales
2. A similar device or cage that can be opened by means of levers, latches, etc., used to test the learning behaviour of animals.
   • That’s where Osvath’s ravens come in. His student Can Kabadayi trained the birds to open a baited puzzle box by putting a stone of particular weight and shape into a tube.2017 July 13, Ed Yong, “Ravens Can Plan for the Future”, in The Atlantic
3. (figuratively) Something that is puzzling; an enigma; (narratology, also attributive) a complex story that is gradually revealed, often driven by a central myth.
   • puzzle box show
   • puzzle-box plot
4. (literally) A box containing a jigsaw puzzle.
   • The world is the geologist's great puzzle-box; he stands before it like the child to whom the separate pieces of his puzzle remain a mystery till he detects their relation and sees where they fit, and then his fragments grow at once into a connected picture beneath his hand.1863 March, The Atlantic Monthly, volume 11, number 65