Neil Gaiman, best-selling author of American Gods, first encountered the phrase trigger warning online, where it served as a heads-up that clicking on a link might reveal ideas or images that could cause traumatic flashbacks. He was "fascinated," he says, "when trigger warnings crossed…into the world of things you could touch." He wondered if universities might someday warn students about his work, which often contains elements of the gorgeous grotesque (an ancient religious site made sacred by the ground up remains of hundreds of dead cats) or the hauntingly human (a first-person story of an aggressive case of aphasia).

These stories and many more appear in his new collection, pre-emptively titled Trigger Warning (William Morrow). Gaiman makes the case against treating fiction as a "safe space." Upsetting stories can be valuable, even to vulnerable readers. "What we read as adults should be read," he writes, "with no warnings or alerts beyond, perhaps: enter at your own risk."