On the first morning of summer, Pip ran down to the beach and almost tripped over her dog Biscuit. He had a green bottle in his jaws, washed up between two rocks. Pip pried it open. Inside was a paper torn down the middle: half a coastline in faded blue ink, and one word left at the rip. It said HARBOR.

Pip decided to ask a grown-up first. She biked straight to Mr. Alvi's bait shop at the pier, where the old sailors traded stories. If anyone knew about a torn map and a word like HARBOR, it would be the man who had fished this coast for fifty years.

Mr. Alvi squinted, then shook his head. "Never seen it. But old Salty Pete might." Pip biked to Pete's houseboat at the end of the pier. The grumpy old sailor stared at her map a long moment, then handed over the missing half from a drawer. "Been keeping that safe my whole life," he said. "Guess it's your turn now."