When the last piece of a puzzle like that is a literal puzzle, though, it’s even better. [Nadieh] has been working on this jigsaw puzzle that displays a fireworks-like effect whenever a piece is ...

It’s no wonder the word “hell” is in the name of this tricky 1,000-piece jigsaw puzzle. Like exercising, doing jigsaw puzzles is difficult but rewarding—and health-promoting.