By Tuesday morning, I was lying inside the emergency department at St. Jude Medical Center while a nurse shouted for the one man I had spent eight months trying to protect from the truth.

At 2:15 on Sunday morning, the fever hit.

It did not climb in degrees; it detonated through my central nervous system like an injection of boiling oil.

My core temperature on the rectal probe jumped from ninety-nine point four to one hundred and five point eight in thirty-two minutes.

The CAR-T cells—the re-engineered killer lymphocytes that Ethan had flown from Philadelphia forty-eight hours earlier—had engaged the lymphoma cells in my retroperitoneal lymph nodes with the catastrophic, uncoordinated violence of a thermonuclear detonation.

Inside the isolation room, the lights were dimmed to a soft, amber red to protect my photophobic retinas. The air was filled with the rhythmic, frantic shrieking of three separate monitoring towers:

ALARM: MEAN ARTERIAL PRESSURE < 55.

ALARM: SINUS TACHYCARDIA > 165.

ALARM: SEVERE CYTOKINE RELEASE SYNDROME — GRADE 4.

My body was convulsing.

Violent, involuntary, full-body rigors shook the heavy steel frame of the gurney, rattling the stainless-steel side rails until the bolts groaned against the floor mounts. My teeth were chattering with such concussive force that a soft rubber bite block had been inserted between my molars to keep me from severing my tongue.

"Push eight of tocilizumab right now!" Lena Patel shouted, her hair wild, her face illuminated by the green glow of the arterial line monitor. "Get the cooling blankets on her! Pack the axillae and the groins with sterile ice bags! If we don't break this temperature in ten minutes, her brain stem is going to herniate!"

"Pressure is sixty-two over thirty-four!" nurse Marcus yelled from the foot of the bed. "She’s not responding to the levophed! We’re at forty mikes on the norepinephrine and two hundred on the vasopressin! Her peripheral vascular resistance is zero!"

Through the red, shimmering haze of forty-one-degree delirium, I saw Ethan.

He was not wearing his surgical mask.

He was wearing only a black scrub top, soaked through with sweat at the chest and neck, his bare arms covered in cold meltwater from the ice bags he was furiously packing around my neck and clavicles.

His face was inches from mine.

His eyes were bloodshot, dilated, wild with an animal, terrifying fury that seemed to challenge the very mechanics of human mortality.

"Claire!" Ethan roared, his voice cutting through the alarms, cutting through the delirium, drilling directly into the base of my skull like an electrical wire.

"Look at me! Don't you dare close those eyes! You look at my face!"

I couldn't breathe. My lungs felt as though they were filled with crushed glass and scalding steam. My heart was hammering at one hundred and seventy beats per minute—an erratic, failing rhythm that felt like a trapped bird beating its wings against an iron cage.

I reached out with my left hand—the hand still stitched with the arterial line.

My trembling, burning fingers brushed the front of his scrub top, catching the cotton fabric, clutching it with a desperate, dying strength.

"Ethan..." I choked out around the rubber bite block, the sound nothing more than a wet, bloody whistle. "...hurts... Ethan, please... let me sleep..."

Ethan’s face fractured.

A single, hot, jagged tear broke from his eye, fell through the amber light, and splashed directly onto my burning cheek.

"No," Ethan wept, his forehead pressing hard against mine, his teeth bared in an unyielding snarl against the darkness closing over my bed.

"You don't sleep, Claire! You promised me twelve years ago in that church on Sullivan’s Island! You promised me for better or for worse! This is the worse, baby! This is the worst night of our lives, and you are going to fight through it with me!"

He turned his head toward Lena Patel, his vocal cords tearing as he screamed across the bed:

"DOUBLE THE VASOPRESSIN! PUSH ONE HUNDRED OF HYDROCORTISONE! IF HER HEART STOPS, I AM OPENING HER CHEST RIGHT HERE ON THIS BED AND MASSAGING IT WITH MY OWN TWO HANDS!"

"Ethan, you can't—"

"DO IT!" he roared.

The needle slid into the central line port.

The ice packs were clamped against my burning skin.

Ethan wrapped his large, scarred surgeon's hands around mine, lacing his fingers through my burning knuckles, pinning our joined hands directly against his breastbone, right over the steady, violent, and unbroken beating of his own heart.

"Take my pulse, Claire," Ethan whispered, his breath hot against my ear, weeping, praying, ordering my dying cells back into formation through sheer, unadulterated willpower.

"Feel that? That’s eighty beats per minute. That’s your rhythm. You match me. You stay with me. One... two... three... four... match me, Claire. Match your husband."

The room seemed to shrink.

The alarms faded into a distant, underwater echo.

The shrieking monitors, the smell of sterile ice, the shouts of the nurses—everything dissolved until there was only the physical sensation of his knuckles ground against mine, and the steady, heavy, rhythmic thump-thump... thump-thump of his chest beneath my palm.

I closed my eyes.