This is the story of McDonald's, the Happy Meal, and a decades-old phenomenon that's making an impressive comeback.
It's about the Rubik's Cube, is arguably the most popular toy of all time, with more than 350 million sold worldwide.
Other companies jumped on the puzzle fad back then. Among them, McDonald's, which put Rubik's cubes in Happy Meals. The toys are still popular today if you can find them: a 1980-vintage Rubik's cube will cost you about $20 on eBay. Compare that to $6 or $7 for a new one.
Eventually, the fad trailed off, but over the last few years there's been a resurgence--speed competitions, world records, and an entire global community that owes its growth partly to YouTube tutorials explaining how to solve the iconic puzzle quickly.
There's also the fact that the patent for the original toy has expired, so there are loads of lower-priced knockoffs, some of which are actually better engineered than the original cube.
(Current world record: Australian Feliks Zemdegs, 22, who solved a puzzle in competition in 4.22 seconds, and solved five in a row, averaging 5.80 seconds each.)
Since everything old is new again, it's probably inevitable therefore that McDonald's would give the Rubik's Cube another shot. And they are, by bringing it back in a new Happy Meal promotion.
McDonald's is changing the Happy Meal box to look like a Rubik's Cube during the campaign, and giving away 1 of 12 different Rubik's puzzles as toys in each one.
The only catch is that if you live in the United States, you'll be waiting for a while at least. The new promotion launches in France this month, and then spreads through Europe, Scandinavia, Middle East, Africa and Canada.