Prologue
Oktawiusz woke up with a mouth full of sand.
It wasn’t ordinary sand. It tasted of mildew and salt — as if, in his sleep, he had inhaled the dust of an abandoned cellar. He swallowed, but the grains clung to his tongue, scratching his throat. It’s always like this since that day. Always.
The clock on the nightstand showed 4:17. He didn’t need to look — he already knew it would be one of those hours. 4:17, 5:37, 2:47. Prime numbers. Indivisible. Agata used to call it his little obsession.
“It’s not an obsession,” he’d tell her, stroking her arm, warm beneath the nightgown. “It’s logic. Prime numbers are like people — you can’t divide them without leaving a trace.”
Now there was only him.
And the emptiness, spreading through the house like an ink stain.
He rose carefully, avoiding the third plank from the bed — the one that creaked. He didn’t want the house to know he was awake. In the bathroom, he spat into the sink. The water swirled pink. His gums were bleeding again.
“Standard, huh?” said the Guest.
The voice came from the doorway, but its reflection in the mirror was blurry, as if someone had scratched the surface with a fingernail. Oktawiusz didn’t turn. He spat again, reached for the toothbrush — the one by the wall, pink, with the faded word Smile! on its handle. His own, the blue one, had lain untouched in the drawer for a year.
“Seven hundred and thirty-two days,” the Guest muttered. “Seven hundred and thirty-two mornings with sand in your mouth. Seven hundred and thirty-two times you’ve thought today would be the day you find her.”
Oktawiusz turned on the tap, but the water didn’t drown the words. The Guest’s voice seemed to come from inside his skull — like a thought that wasn’t his.
“Remember the shoes?” the Guest whispered. “Those red flats in the hallway? So shiny, so proud. And yet Agata never wore them. Never.”
The toothbrush froze mid-motion. Oktawiusz closed his eyes. He could see them — those cursed shoes, standing unnaturally straight.
“Shut up,” he hissed through clenched teeth.
“You locked the door that night, didn’t you? Just to make sure no one could—”
“Shut up!”
The toothbrush struck the mirror. The glass cracked, and the toothpaste smeared across it in a streak shaped like a scream. The Guest was gone. Only the scent of mint and jasmine remained — her perfume.
Oktawiusz pressed his forehead against the glass.
Outside, the dawn was gray and uncertain. Birds circled above the forest — black, uneasy specks, like burnt fragments of a letter tossed into fire.
He knew he would search for her again today.
Just like yesterday.
Just like seven hundred and thirty-one days before.
Because prime numbers don’t lie.
