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.

The headlights in the mirror aren't slowing down. They speed up, aimed straight at her. Mara throws the car in reverse and the retrochron screams. The whole lot smears sideways. She's not delivering anymore. She's running. But you can't outrun a thing that already happened.

The lot keeps smearing. Mara floors it and the retrochron drags her back further, an hour, a day, a year. The rain turns to snow, then sun, then rain again. When the world snaps still, she's parked outside the dispatch office on the night she first took this job.

Past Mara, the new hire, walks out of the office and stops dead at the sight of herself in the car. Present Mara leans out. 'Don't take this job,' she says. 'It loops. It never ends.' The young one hesitates, then tears up her contract. Both retrochrons go quiet. Neither Mara ever delivers the package, and somehow that's the only way it ends.