The dispatch slip is short: hand the package to yourself, ten minutes ago, do not open it. Under Mara's dash, the retrochron unit hums like a trapped wasp. The meter counts backward. Rain runs UP the windshield into the sky. On the seat beside her sits a brown paper package, taped shut, no label. The clock hits her drop time. Headlights swing into the lot behind her.

Mara doesn't move. She stares at the package and the rule on the slip: do not open it. Whoever wrote this knew she'd want to peek. Her thumb finds the tape. 'Just a corner,' she tells herself. 'Just to see.' The retrochron's hum jumps higher, angry now, like it knows.

The tape peels back. Inside is a small recorder with one button. Mara presses it. Her own voice, ragged: 'If you opened this, you broke the loop. Now every version of us is awake at once. Drive. Don't stop. Don't let them catch you.' Engines start all around the lot.

Mara drives. In her mirror a dozen copies of herself give chase through streets that fold and repeat. She spots the dispatch office ahead and aims for it. If she can reach the retrochron's master switch, she can shut the whole loop down. The recorder in her lap clicks on by itself: 'Good girl. Almost home.'