On the last day of summer, Sam made a promise to the old keeper of the harbor lighthouse. "Water the little garden every evening while I'm away," the keeper had said, pressing a small brass watering can into Sam's hands. "Nine days. The seeds are new, and they get thirsty." Sam nodded so hard his chin nearly bumped his chest. "Every evening," Sam said. "I promise."
The first few evenings were easy and grand. Sam walked the winding path with Grandma, the sea sighing hush-hush against the rocks, and filled the brass can from the rain barrel. Splish, splish, splish went the water over the tiny green sprouts. The lighthouse stood tall and white above them like a friendly giant, and Sam felt terribly important.
But by the fifth evening, the fun had worn thin. His legs ached. A cousin had brought a new board game that everyone was laughing over back home. "Do we have to?" Sam asked, watching the path stretch long and gray ahead. Grandma only said, "That's your promise, not mine." So Sam sighed, took the brass can, and went. Splish, splish, splish. The sprouts had grown two leaves each. That was something.
On the seventh evening, a fat curtain of rain swept in off the water. Sam stood at the window watching drops race down the glass. "The rain will water them tonight," he told himself, and it almost sounded true. But then Sam remembered the little seedlings tucked under the stone ledge, where the roof of the wall kept every raindrop out. Nobody would ever know if he skipped one night. Nobody except Sam.
So he pulled on his boots. Grandma lifted an eyebrow but reached for her coat too, and together they leaned into the wind, the brass can swinging. The path had turned to shining puddles. When they reached the ledge, Sam saw he had been right — the seedlings sat bone dry in their sheltered corner, leaves drooping like tired little hands. Splish, splish, splish. The leaves lifted almost at once.
The eighth evening was the hardest of all. Sam had spent the whole day at the tide pools and could barely keep his eyes open. "One night," he mumbled. But a promise, Sam had decided, was a thing you carried whether it was light or heavy. He carried it up the path in the dusk, yawning the whole way, and watered every single sprout.
On the ninth evening the keeper came home. Sam met the old boat at the dock and led the way up the winding path, hardly able to keep still. When they rounded the last bend, the keeper stopped short and pressed both hands to his wrinkled cheeks. Where there had been bare soil nine days before, the garden foamed with color — spikes of blue, ruffles of gold, and one tall flower the deep pink of the sky at sunset, all of them nodding in the salt breeze.
"You kept it," the keeper said softly. "Through the dull days too, and the rainy one." Sam scuffed a boot, suddenly shy. "They got thirsty," he said, as if that explained everything, and maybe it did. The keeper unhooked something from the lighthouse rail — a little glass float, sea-worn and blue-green, that caught the last light like a bubble of ocean. "For a gardener who shows up," the keeper said, and folded it into Sam's hands.
That night Sam set the glass float on the windowsill where it glowed faintly in the moonlight. The sea whispered hush-hush against the rocks below, the same as always. His legs still ached a little, and his eyes were heavy as stones. Somewhere up on the point, the lighthouse turned its slow warm beam across the water, and the little garden drank in the dark. Sam pulled the blanket to his chin, listening to the far-off splish of the tide, and drifted down into sleep as soft and easy as a falling petal.