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 knew the old harbor. It was a twenty-minute ride up the coast road. She grabbed her bike from the porch, tucked the map in her pocket, and whistled. "Come on, Biscuit. The other half of this map has to be somewhere." Biscuit barked and chased after her wheels.

At the harbor, Pip found a row of crooked old boathouses. On the wall of the last one hung a faded paper that looked exactly like her map's missing half. But it sat behind a cracked glass case, locked shut with a rusty padlock.

Pip spotted a loose board beside the case and wiggled it free. Behind it hung a small key on a string. She fit it into the rusty padlock, and with a squeak the case swung open. She lifted out the missing map half and pressed the two torn edges together. They matched perfectly.