The Algorithms of Leaving

The vitamin bottle sat on her nightstand, a promise she kept making to herself. Another day, another fresh start. She swallowed the D3 with lukewarm water, already thinking about the five-mile run she'd skip again.

Her iPhone buzzed at 6:43 AM — not his alarm, but a calendar notification. Their anniversary dinner, scheduled for tonight. The reservation she'd made three weeks ago when things still felt fixable.

Mark was already up, standing by the window in his running clothes. The cat, a ginger tabby she'd rescued after her mother died, wound through his legs like a plea. He didn't look down.

"You going?" she asked, her voice sounding foreign in her own throat.

"Yeah. Long one today." He was already stretching, avoiding her eyes.

She'd noticed it gradually — the long runs, the longer showers after, the way he'd come back exhausted and hollowed out, as if something essential had been sweat out of him. Last week, she'd found his running log. Forty miles logged. Zero texts to her.

"The reservation's at seven," she said.

He paused mid-stretch. "I might be late."

The cat jumped onto the bed, settled on his pillow. Orange fur against white linen, possessive and practical both.

She picked up her iPhone, opened the banking app. There it was: the charge for a one-way flight to Denver, booked yesterday at 3 PM while she was at work. Running in a different direction now.

"Mark?"

He finally turned. His expression was that particular brand of exhausted she'd seen on her father's face the night he left — not cruel, just emptied of everything that wasn't escape.

"I'm not coming back, Sarah."

The vitamin dissolved in her stomach, useless and optimistic. Outside, the morning turned orange with sunrise, the color of beginnings and endings and things you couldn't stop.

"Okay," she said. And somehow, that was worse than screaming. The cat purred against the pillow, rhythmic and indifferent. The iPhone's screen dimmed. Mark walked out the door, already running toward something that wasn't her.