He would learn to play the violin before he had his first doctorate, and during a lifetime of remarkable amity they would play together for ten thousand hours, but all of that would come after the big idea. The big idea—“Why aren’t all blind people geniuses?”—was planted that very night, but it didn’t start to sprout for another week.

Like most 13-year-olds, Cletus was fascinated by the human body, his own and others, but his study was more systematic than others’ and, atypically, the organ that interested him most was the brain.

The brain isn’t very much like a computer, although it doesn’t do a bad job, considering that it’s built by unskilled labor and programmed more by pure chance than anything else. One thing computers do a lot better than brains, though, is what Cletus and Lindy had been talking about over their little squids in tomato sauce: partitioning.

Think of the computer as a big meadow of green pastureland, instead of a little dark box full of number-clogged things that are expensive to replace, and that pastureland is presided over by a wise old magic shepherd who is not called a macroprogram. The shepherd stands on a hill and looks out over the pastureland, which is full of sheep and goats and cows. They aren’t all in one homogeneous mass, of course, since the cows would step on the lambs and kids and the goats would make everybody nervous, leaping and butting, so there are partitions of barbed wire that keep all the species separate and happy.

This is a frenetic sort of meadow, though, with cows and goats and sheep coming in and going out all the time, moving at about 3 x 108 meters per second, and if the partitions were all of the same size it would be a disaster, because sometimes there are no sheep at all, but lots of cows, who would be jammed in there hip to hip and miserable. But the shepherd, being wise, knows ahead of time how much space to allot to the various creatures and, being magic, can move barbed wire quickly without hurting himself or the animals. So each partition winds up marking a comfortable-sized space for each use. Your computer does that, too, but instead of barbed wire you see little rectangles or windows or file folders, depending on your computer’s religion.

The brain has its own partitions, in a sense. Cletus knew that certain physical areas of the brain were associated with certain mental abilities, but it wasn’t a simple matter of “music appreciation goes over there; long division in that corner.” The brain is mushier than that. For instance, there are pretty well-defined partitions associated with linguistic functions, areas named after French and German brain people. If one of those areas is destroyed, by stroke or bullet or flung frying pan, the stricken person may lose the ability—reading or speaking or writing coherently—associated with the lost area.

That’s interesting, but what is more interesting is that the lost ability sometimes comes back over time. Okay, you say, so the brain grew back—but it doesn’t! You’re born with all the brain cells you’ll ever have. (Ask any child.) What evidently happens is that some other part of the brain has been sitting around as a kind of back-up, and after a while the wiring gets rewired and hooked into that back-up. The afflicted person can say his name, and then his wife’s name, and then “frying pan,” and before you know it he’s complaining about hospital food and calling a divorce lawyer.

So on that evidence, it would appear that the brain has a shepherd like the computer-meadow has, moving partitions around, but alas, no. Most of the time when some part of the brain ceases to function, that’s the end of it. There may be acres and acres of fertile ground lying fallow right next door, but nobody in charge to make use of it—at least not consistently. The fact that it sometimes did work is what made Cletus ask “Why aren’t all blind people geniuses?”

Of course there have always been great thinkers and writers and composers who were blind (and in the twentieth century, some painters to whom eyesight was irrelevant), and many of them, like Amy with her violin, felt that their talent was a compensating gift. Cletus wondered whether there might be a literal truth to that, in the micro-anatomy of the brain. It didn’t happen every time, or else all blind people would be geniuses. Perhaps it happened occasionally, through a mechanism like the one that helped people recover from strokes. Perhaps it could be made to happen.

Cletus had been offered scholarships at both Harvard and MIT, but he opted for Columbia, in order to be near Amy while she was studying at Julliard. Columbia reluctantly allowed him a triple major in physiology, electrical engineering, and cognitive science, and he surprised everybody who knew him by doing only moderately well. The reason, it turned out, was that he was treating undergraduate work as a diversion at best; a necessary evil at worst. He was racing ahead of his studies in the areas that were important to him.

If he had paid more attention in trivial classes like history, like philosophy, things might have turned out differently. If he had paid attention to literature he might have read the story of Pandora.

Our own story now descends into the dark recesses of the brain. For the next ten years the main part of the story, which we will try to ignore after this paragraph, will involve Cletus doing disturbing intellectual tasks like cutting up dead brains, learning how to pronounce cholecystokinin, and sawing holes in peoples’ skulls and poking around inside with live electrodes.

In the other part of the story, Amy also learned how to pronounce cholecystokinin, for the same reason that Cletus learned how to play the violin. Their love grew and mellowed, and at the age of 19, between his first doctorate and his M.D., Cletus paused long enough for them to be married and have a whirlwind honeymoon in Paris, where Cletus divided his time between the musky charms of his beloved and the sterile cubicles of Institute Marey, learning how squids learn things, which was by serotonin pushing adenylate cyclase to catalyze the synthesis of cyclic adenosine monophosphate in just the right place, but that’s actually the main part of the story, which we have been trying to ignore, because it gets pretty gruesome.

They returned to New York, where Cletus spent eight years becoming a pretty good neurosurgeon. In his spare time he tucked away a doctorate in electrical engineering. Things began to converge.

At the age of thirteen, Cletus had noted that the brain used more cells collecting, handling, and storing visual images than it used for all the other senses combined. “Why aren’t all blind people geniuses?” was just a specific case of the broader assertion, “The brain doesn’t know how to make use of what it’s got.” His investigations over the next fourteen years were more subtle and complex than that initial question and statement, but he did wind up coming right back around to them.

Because the key to the whole thing was the visual cortex.

When a baritone saxophone player has to transpose sheet music from cello, he (few women are drawn to the instrument) merely pretends that the music is written in treble clef rather than bass, eyeballs it up an octave, and then plays without the octave key pressed down. It’s so simple a child could do it, if a child wanted to play such a huge, ungainly instrument. As his eye dances along the little fenceposts of notes, his fingers automatically perform a one-to-one transformation that is the theoretical equivalent of adding and subtracting octaves, fifths, and thirds, but all of the actual mental work is done when he looks up in the top right corner of the first page and says, “Aw hell. Cello again.” Cello parts aren’t that interesting to saxophonists.

But the eye is the key, and the visual cortex is the lock. When blind Amy “sight-reads” for the violin, she has to stop playing and feel the Braille notes with her left hand. (Years of keeping the instrument in place while she does this has made her neck muscles so strong that she can crack a walnut between her chin and shoulder.) The visual cortex is not involved, of course; she “hears” the mute notes of a phrase with her fingertips, temporarily memorizing them, and then plays them over and over until she can add that phrase to the rest of the piece.