On his first morning of retirement, Edwin Marsh swept the old Hollowbrook post office one last time. Behind a coat rack he found a brass mail slot in a wall that never had one. The little plate read TOMORROW'S DEPARTURES. As a joke, he scribbled a grocery list and fed it in. By noon, the milk he'd written down sat on his porch, in a glass bottle stamped with tomorrow's date.

Edwin decided the slot was a trick, maybe a prank from the new postmaster. He marched next door to ask his neighbor Rosa if she'd seen anyone sneaking around his porch that morning.

Rosa laughed at first, then went pale when Edwin showed her the milk bottle stamped with tomorrow's date. 'My grandmother told stories about that slot,' she whispered. 'She said it only opens for someone who's about to need it.' Edwin asked what she meant.

Rosa explained that her grandmother used the slot just once, to save a sick child by ordering medicine from the next day. 'Use it for someone else,' she said firmly, 'never just for yourself.' Edwin nodded slowly, thinking of all the people in town who might need help.

Together, Edwin and Rosa started a quiet routine. Each morning they asked the slot for one small warning, then spent the day helping a neighbor avoid trouble. The town never knew why their luck had turned, but Edwin's retirement became the busiest, happiest time of his life.