When a manufacturer offers a 10,000-mile warranty on a car or slaps a "bear-resistant" label on a camping cooler, what do we know about how trustworthy that promise is, and how it's backed up? For the cooler, it's Kobuk the Destroyer, the fiercest member of the Interagency Grizzly Bear Committee's panel of product-testing bears: Gifted at cracking locks and foiling manufacturers, Kobuk and his fellow bears play a crucial role in keeping us (and our snacks) safe. For everything else--as journalist Alex Davies reveals in this freewheeling tour of the hidden work that keeps the modern world going, safely and dependably--we have test engineers, who imagine how anything and everything could go wrong, and fight back.

From echo-proof chambers to Formula 1 wind tunnels to airplane hangars turned torture labs, Davies takes readers behind the scenes of a workforce that combats contingency with equal parts analytical rigor and wild imagination. Armed with sixty-foot cannons that fire frozen chickens into jet engines, rocket sleds so fast they knock fillings out of teeth, and Lazy Susans for tasting hundreds of cups of tea a day, test engineers break it so you can buy it.

But failure is a stubborn opponent: The tsunami will overtop the dam, the chatbot will give bad advice, the bear will eat your sandwich. Test engineers don't just prevent disaster; they limit its fallout and make peace with its reality by balancing risk against reward. In an age of climate crisis, run-amok tech, and eroding trust in public institutions, knowing how they do it--and how we might do the same--is more valuable than ever before.

Brimming with humor and insight, Kobuk the Destroyer is a celebration of human ingenuity and a deeply human story about uncertainty, resilience, and the art of making a fragile world a little more reliable.