The coffee was 93.2 degrees Celsius.

  He knew this because he had calibrated the machine himself — a process that had consumed an entire Saturday afternoon, two arguments with the department secretary, and a Phillips-head screwdriver he still hadn't returned to Facilities. The secretary had called it obsessive. He had called it thermodynamics. She had not found this funny, which he considered a failure of education rather than humour.

  Dr. Chen Xi sat in the control room of the Stanford Linear Accelerator Center, not doing anything particularly important. He was checking decimal points on a readout while his colleague, Dr. Sarah Park, argued into her phone about whether pad thai counted as dinner when you'd already had it twice that week. The fluorescent lights buzzed at 60 hertz. The climate control held the room at 21.5 degrees. Attempt number 347 of the Grand Unified Field experiment was cycling through its preliminary diagnostics, and nobody in the room expected anything from it because nobody had expected anything from it since attempt number 200.

  He had been running this experiment for seven years. His ex-wife, Elena, had once calculated that he'd spent more hours with the accelerator than with her, and she'd been right, and they'd both known it was not the kind of calculation that could be corrected retroactively. She was in Zurich now, doing something with condensed matter physics and a man named Rolf who apparently cooked. Chen Xi had met Rolf once at a conference. Rolf was tall and wore good shoes. Chen Xi wore whatever was closest to the bed.

  Attempt 347. He scrolled through the beam parameters. Identical to 346. Identical to 345. Identical to every attempt since the last equipment service in March, when a technician named Dave had replaced a focusing magnet and left a granola bar wrapper inside the housing, which Chen Xi had discovered three days later and filed a maintenance report about that was, he suspected, still sitting in someone's inbox.

  He reached for his coffee.

  The alarm sounded.

  Not the drill alarm — that was a flat, bored tone, the sonic equivalent of a form letter, designed to be acknowledged and ignored. This was the other one. The one they tested once a year, always on a Thursday morning in October, and hoped to never hear on a Tuesday evening in June.

  A case of content theft: this narrative is not rightfully on Amazon; if you spot it, report the violation.

  Sarah stopped arguing about pad thai. The phone was still at her ear but her mouth had stopped moving. She was looking at the viewport.

  Chen Xi looked at the viewport.

  In the chamber, where nothing should have been visible to the naked eye because the relevant physics operated at scales fourteen orders of magnitude below human perception, there was light.

  Not the light of an explosion. He would learn what that looked like in approximately 1.7 seconds, and the difference would be the last thing his brain catalogued before his brain ceased to be a functioning instrument. This was structured light. Patterned. It had density and organisation and a geometry that his visual cortex could not process but his trained mathematical intuition recognised with a jolt of something he had no time to identify as either terror or rapture.

  It looked like an equation.

  Not a written equation — not symbols on a whiteboard, not variables in a journal. It was the thing itself. The mathematical relationship that held quarks in their orbits and curved spacetime around mass and determined the rate at which entropy increased in a closed system and gave photons their specific, maddening duality. It was the structure underneath the structure underneath the structure, and it was, for three thousandths of a second, visible.

  He saw it.

  His mind did what it had been trained across twenty-six years of postdoctoral work to do: it reached for the pattern. Not consciously — there was no time for consciousness, no time for the slow, sequential process of thought. This was the substrate beneath thought, the pattern-matching architecture that had made him a passable physicist and a terrible husband and a man who calibrated coffee machines on Saturdays because precision was the only language he had ever been fluent in.

  He caught three terms of the equation.

  Three terms out of what his fading awareness estimated, with the absurd confidence of a dying man, to be several thousand. Three terms scrawled on the wet clay of his memory in the half-second before the clay baked and cracked and turned to dust.

  The light became heat. The heat became pressure. The pressure became a sound that was not a sound, because by the time it reached his eardrums, his eardrums had already stopped being a coherent arrangement of molecules.

  The last thing Dr. Chen Xi felt was not fear, or peace, or the warm embrace of whatever waited on the other side of thermodynamic equilibrium. It was irritation. He had been so close. The decimal points had been in order. The coffee had been perfect.

  He was forty-three years old. He had published thirty-one papers, none of them famous. He had been cited 4,217 times, which was respectable. He had eaten lunch alone most days for the past six years. He had solved three terms of the equation that described the universe, which was three more than anyone else in human history, and considerably fewer than he would have liked.

  He died on a Tuesday, and the coffee went cold.