Unless you stayed up to the bitter end, you missed the last question. It came over the Internet from Peggy in Amherst, N.H., and, as Tom Brokaw warned, it had a certain "Zen-like" quality: "What don't you know and how will you learn it?"

This wasn't a trick question hurled at the men who would be president. The subtext was the shared anxiety that we are picking a president who will be making decisions in that "unknown" zone called the future.

"It's the challenges that you don't (expect) that end up consuming most of your time," responded Obama.

"What I don't know is what all of us don't know, and that's what's going to happen both here at home and abroad," concurred McCain.

Uncertainty is the backdrop for this campaign whose last month is being conducted over the shakiest terrain. What we didn't know yesterday, last week, last month suddenly reshapes the contours of our lives. Credit-default swaps? Mortgage-backed securities? Nothing Zen about them.

On the day of the second debate, the stock market dropped 508 points. A story on the evening news chronicled a meltdown in Iceland that had nothing to do with global warming. Who knew that we'd be worrying about Iceland's finances?

I've often been bemused at how financial markets talk about "the future" as if it were a living, breathing, gambling thing. The future is up, they say, the future is down. But there's no metaphor in saying the future is uncertain.

As for Peggy? Maybe she was remembering George W. Bush. He ran as a compassionate conservative and presided over the future's wrecking crew. The man so many Americans wanted to have a beer with now bellies up to the bar alone.

Or maybe Peggy was reminding us of something else. Being president is more of an improvisation than a neatly scripted plan. It's about reactions as much as actions. What we need to know most about a president is how he thinks, how he listens, the strength of his worldview and the nimbleness of his mind.

The debate hype was all about toughness. Sarah Barracuda said the gloves would come off, as if a bare-fisted fighter weren't just as likely to injure himself as injure an opponent. The early headlines said "Rivals Trade Jabs." The instant replays showed the awkward, angry moment when McCain referred to Obama as "that one." The media search for zingers showed Obama reminding voters of McCain's musical rendition of Bomb Iran.

But a sober — even somber — group of independent voters from Nashville were looking for reassurance, not red meat. It is not morning in America and anecdotes are not information. The competition was about which candidate owns the future. And the victory went to "that one."

This wasn't just a matter of age. After all, both men identified Warren Buffett, 78, as their wise man. Nor was it simply a matter of style, although Obama quietly owned the stage that McCain paced uneasily. But both times McCain insisted that we need a "steady hand at the tiller," it sounded like a pitch for his opponent. We were reminded that McCain has rebooted his image as if it were a pesky computer. Steady is not how he goes.

McCain's insistence that Obama is too green, that we "don't have time for on-the-job training, my friends," played against the image of the Illinois senator in cool command as he explained the rescue package. The urgent, insistent sales pitch from McCain that he is the one to get Osama bin Laden — "I'll get him. I know how to get him. I'll get him no matter what" — left this viewer wondering what he was waiting for.

This election is flowing toward the Democrat the way the Dow Jones average is flowing downstream. What we don't know yet is exactly what the McCain campaign is willing to do to try and stanch the flow. But we know how we'll learn it.

The airwaves are already full of attack ads calling Obama dangerous and dishonorable. The candidate is asking darkly, "Who is Obama?" His running mate presiding over "Palin's Pit Bulls" is saying that Obama has been "palling around with terrorists."

In an earlier incarnation, McCain once wrote, "I've had my fill of partisan excesses, and I don't intend to disgrace myself by indulging in them." The very un-Zen-like question is not whether McCain will commit character assassination. It's whether he's committing character suicide.

Ellen Goodman is a columnist for The Boston Globe. Reach her at ellengoodman@globe.com.