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 grabs the package and gets out. The other car is hers, exactly hers, same dent in the bumper. The driver's door opens. A woman steps out with Mara's face and Mara's tired eyes. 'You're early,' the other Mara says. Mara holds out the package with shaking hands.

The other Mara takes the package and tucks it under her arm. 'Now get back in your car and don't look back,' she says. 'And when it's your turn, do not open it.' Headlights swing into the lot. Both women freeze. That's the early car arriving. There shouldn't be a THIRD.

The third car's door opens and an older Mara climbs out, gray-haired, calm. 'Both of you, stop,' she says. 'The loop only closes if the package changes hands once. You've passed it twice. We have to put it back in the first car before the timer ends.' She points. Forty seconds left.

Mara and the other two sprint the package to the first car and lay it on the seat just as the timer hits zero. The retrochron units across the lot go silent together. When Mara looks up, the other selves are gone. One car, one her, one sealed package she'll deliver in ten minutes, exactly as the slip always said. She drives off and never opens it.