The Supplemental Life

Mark stood in the bathroom, the fluorescent light humming overhead, staring at the orange prescription bottle on the counter. Vitamin D3 — the generic brand he'd been taking for years. But this bottle was different. Someone had swapped his usual supply for something else. The pills were slightly larger, a different shade of yellow.

His wife Sarah had been acting strange lately. Coming home late from her tech job, deleting messages from her phone before bed, sudden interest in his work at the corporate intelligence firm. Three months ago, she'd even bought a cat — a sleek black Bombay she named "Midnight" though it spent most of its days sleeping in the sunbeam through their bedroom window.

"Just lonely during the day," she'd said.

Mark was a corporate spy. He knew the signs of surveillance, of misdirection, of someone hiding something. He'd spent fifteen years extracting secrets from executives, spotting patterns in email trails, noticing when someone's routine shifted just enough to signal compromise. And Sarah's routine had shifted.

The cat meowed from the hallway, winding between his legs. Mark picked it up, studying its golden eyes. "What do you know, Midnight?" he whispered.

He'd started taking the vitamins two weeks ago. Fatigue. Brain fog. He'd attributed it to stress, to the insomnia that had him staring at the ceiling at 3 AM while Sarah slept beside him, breathing evenly, turned away.

His phone buzzed — a secure message from his boss. "Project OMEGA. Meeting in 20."

Project OMEGA. The pharmaceutical company Sarah worked for. The one he'd been gathering intel on for six months.

Mark set the cat down gently. He took one of the yellow pills, placed it on a small tray he used for field testing. The reagent turned blue — barbiturate. Not vitamins at all.

Sarah walked into the bathroom, fresh from the shower, wrapped in a towel. She paused, seeing the test tray. Then she looked at him, really looked at him, for the first time in months.

"You're smarter than they said you'd be," she said quietly.

The cat rubbed against her ankles, purring, and Mark realized suddenly that the cat wasn't a companion. It was a courier. Someone had been trained to enter and leave through the pet door, carrying and retrieving information.

"How long?" he asked, though he already knew the answer.

"Three years," she said. "Since before we met."

Outside, a car door slammed. The boss who'd summoned him to a meeting that would never happen.

Mark laughed, a dry sound that surprised even him. "I make my living catching spies," he said, "and I married one."

"We all need vitamins, Mark," she said, not unkindly. "Yours just happened to be the truth."