After waiting in the long customs queue at JFK airport in New York City a few years ago, I found myself before an agent with a dour expression. He wondered: What kind of work, exactly, requires a trip to Europe and back in less than three days? As I drew breath to explain my job as an editor at Scientific American, his eyes dropped to the slim volume in my hand, and he suddenly beamed. “Oh, I read that book, and it was terrific.” He handed me back my passport. “Welcome home.”

The book? Stiff: The Curious Lives of Human Cadavers (W. W. Norton, 2003), by Mary Roach. I’d heard it was witty and thought it would be diverting for a long international flight. It was. In fact, I was well into the chapter on what happens to bodies during airplane crashes before I noticed I’d been reading it at 35,000 feet over the Atlantic Ocean. After a pause (in which I confess I thought about the wisdom of tempting fate), I read on. I was rewarded with fascinating scientific information and, more than that, a good story.

You just never know when a willingness to engage with possibly uncomfortable topics might have an upside. Now that you have reached the beginning of “The End,” our annual special single-topic issue, we hope it will pro­vide similar benefits. As you read, you may come to appreciate, as I have, how an apparent finish can often be just another way to open a new door. Click here for a thoughtful introduction to the feature section by staff editor Michael Moyer, who organized the issue.

That is not to say it is always easy to take a hard look at finales. When it comes to contemplating our own mortality, the nature of our consciousness actually makes it impossible to imagine the world without us. Consider, as Jesse Bering, ­director of the Institute of Cognition and Culture at Queen’s University Belfast, wrote in our sister publication, Scientific American Mind, that you will never know you have died: “You may feel yourself slipping away, but it isn’t as though there will be a ‘you’ around who is capable of ascertaining that, once all is said and done, it has actually happened.”

Partly for this reason—the difficulty and possible discomfort about some of the topics we wanted to cover—the editors have mulled and then put aside this issue annually for the past few years. How would people react? Would it “die” on the newsstand? (Ouch, I know.) For my part, I find contemplating the future fascinating, whether it is my own, the planet’s or even the universe’s: this issue explores all three and then looks at what comes after the end in many related areas as well. The topic also seems the perfect alpha-and-omega bookend to our single-themed issue last year, “Origins.”

When you’re done with this issue, you can find more on the home page of www.ScientificAmerican.com, including a special interactive package about the feature article, “How Much Is Left?” which was developed with Zemi. And during the week of August 23, you can listen to several of the editors and other experts in interviews and related stories on WNYC’s national morning radio news program “The Takeaway” (more at www.ScientificAmerican.com/TheEnd). As always, let us know what you think.