Mara found an old brass key in the pocket of her grandmother's winter coat. Her grandmother had died in the spring, and Mara had no idea what the key opened.
That evening she took the last ferry across the bay. She was turning the key in her fingers when she saw that the old man sitting opposite her was doing the same thing. His key was identical to hers. "Where did you get that?" he asked quietly. "From my grandmother's coat," said Mara. The old man smiled sadly. "Then your grandmother was my best friend when we were children. My name is Aldo. Sixty years ago we locked a wooden box under the old pier and promised to open it when we were both old."
The next morning, at low tide, they found the box. Inside were two little paper boats and a note: "We'll sail again." Aldo laughed and cried at the same time. Mara folded a new boat, and together they sailed it.