I know why I know so little, but why is it so difficult for you scientists to know things definitively? You’re the ones that got soluble dentifrice into those tubes that never go flat.

All a guy really wants to know from you, for instance, is what the deal was 12,000 years ago, so he can mention quickly, in a nonfiction book about Southern Illinois, that 35 genera of big mammals hanging around back then suddenly went extinct, including all the local mammoths, camels, giant ground sloths, and horses. If you could get together on your story, he could go back to finishing his reading on bootleggers being hung for killing each other. ("It is a beautiful world," one said as they slipped the hood over his head.)

Now, for years you blamed the Clovis people and their hot new technology for the extinctions. You said they were the first to walk across the Bering land-bridge, and that they hunted everything out after inventing deep fryers.

Then, all of a sudden, you announced you’d found evidence of pre-Clovis people all down the Americas, which kind of blew wide open your whole slander against the Clovis folk. Besides, the Clovis seem to have disappeared right along with the Giant Short-Faced Bears.

Now you say the Younger Dryas did it.

I mean, this geologic-prehistoric stuff isn’t the guy’s main focus—it’s not even a footnote, really, to what he’s writing—but you can see how he’d get a little sidetracked when you said it’s awfully funky, scientifically speaking, that even though the glaciers sitting on North America were melting back, this little ice age called the Younger Dryas came on again suddenly for another 1,200 years, probably killing off the food and destroying habitat, but you didn’t know why. I mean, that’s so weird.

You said the YD was brought on when Lake Agassiz, a body of glacial meltwater bigger in area than the state of California, broke an ice dam and drained into the North Atlantic, shutting down the Gulf Stream and changing the earth’s climate.

No, wait a minute: A comet impacted the earth, scorched the surface and raised dust and ash. “The entire continent was on fire,” you said. “And we’ve got the nanodiamonds to prove it.”

Psych!