The Boeing 767 climbed through the low marine clouds over Boston Harbor at 8:15 PM, its banking turn revealing the sprawling, luminous grid of the Massachusetts shoreline before the dark Atlantic swallowed the horizon.
Wesley sat by the oval window in row fourteen, watching the wingtip strobe flash against the wisps of gray vapor. Beside him, Vivian Caldwell had already adjusted her seat, arranged her light travel blanket over her lap, and clicked the overhead reading light into place. Her blue city transit uniform had been replaced by a simple, elegant dark wool pantsuit, but her posture retained the upright, steady discipline of someone who had spent decades keeping a bus on the center line through snow squalls and rush-hour bottlenecks.
In her tote bag beneath the seat rested two new maroon passports, stamped with fresh federal seals, along with a container of homemade pecan biscuits she had baked at four that morning in the Humboldt Avenue kitchen.
"You feeling the air pressure in your ears, baby?" she asked, without looking away from her small crossword puzzle.
"A little," Wesley answered, his cheek resting against the plastic frame. "It's just the differential equation for altitude. $P(h) = P_0 e^{-Mgh/RT}$. The density drops as the air column gets taller."
Vivian gave a low, rich chuckle that rumbled softly in her throat. "I don't need the formula, Professor. Just chew on one of those mints in your pocket. It clears the tubes."
Wesley took a peppermint lozenge, feeling the cool menthol bloom on his tongue. He reached into his canvas bag, pulled out a battered composition notebook bound with electrical tape, and laid it on his pull-down tray.
Inside the notebook were no lecture notes for Zurich. There were no rehearsed opening remarks or polished acknowledgments. The pages were filled with the handwriting of fifth graders from the Timilty Middle School and the Dudley Workshop: clumsy fractions, uneven long-division brackets, and notes on gear ratios written by young boys whose fathers worked in the maintenance yards of the commuter rail.
Dr. Aris Thorne sat across the aisle, his reading lamp illuminating a thick volume of functional analysis. He looked over at Wesley's tray table, his eyes twinkling.
"You're not reviewing the Zurich slide proofs, Wesley?"
"Marcus Jr. asked me a question before we left the workshop yesterday," Wesley said, smoothing down a dog-eared corner of the notebook. "He wanted to know why you can't divide a prime number by two without leaving a half. He said his teacher told him prime numbers are lonely because they don't have friends in the times table. I told him numbers aren't lonely; they're just atoms that can't be cut with an integer knife. I'm drawing him a picture of the sieve of Eratosthenes using grid squares so he can see it when we get back."
Thorne lowered his book, staring at the child across the narrow aisle.
"You have two hundred senior fellows waiting for you at the Federal Institute, Wesley. Men who have won the Wolf Prize and the Fields Medal. And you are preparing an arithmetic diagram for a fourth grader in Roxbury."
Vivian turned her head slowly, her dark amber eyes meeting the senior professor’s gaze with calm authority.
"The children in Roxbury will be there when the lecture in Zurich is forgotten, Dr. Thorne," Vivian said softly. "The people in Switzerland have three hundred years of libraries and grand stone colleges. The children at Dudley Street only have the workshop and the people who remember to come home to them. Wesley’s work doesn't belong to the Swiss; it belongs to the pavement where he found his first book."
Thorne held her gaze for a long moment, then slowly nodded his head, closing his book with a soft, final thud.
"You are right, Vivian," Thorne murmured. "Forgive an old academic for forgetting where the current begins."
Wesley did not join the conversation. He had already unclipped his pencil. Under the yellow glare of the passenger lamp, five miles above the dark ocean, his hand began drawing neat, one-centimeter squares across the page, charting the primes with tiny, unyielding dots of carbon, laying down the truth one line at a time.