At his signal, two volts of electricity, enough to power a wristwatch, course through the wires and radiate outward from the tip a few millimeters in every direction. Millions of neurons bask in the electricity, and the effect is fairly immediate. Hire feels warm at first, a bit flushed.

And then it happens. The room looks brighter to her. The faces, the big, circular lights overhead, the ceiling—they all seem clearer. Malone asks her how she feels. “I’m really happy,” she replies, clearly surprised. “I feel like I could get up and do all sorts of things.” But even more telling than her words is the look on her face. For the first time in 20 years, with a halo bolted to her head and two freshly drilled holes in her skull, Hire smiles. . . . When I meet with her six months after the surgery, she doesn’t look like a person who spent 20 years trapped in a dark mental cave. She’s energetic. She shakes my hand firmly and looks me straight in the eye—something she says she simply wouldn’t have been able to do before. She laughs often (and my jokes aren’t even really funny). She now walks 50 miles a week, talks to her family constantly, chats with strangers at the post office. And her smile is a regular, everyday thing, not a freakish, fleeting appearance in a crowded operating room.

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