Across the black water, the old lighthouse blinked twice. Then it went dark. Mara stood on the dock and stared. That light had no business working. The town said no one had unlocked the lighthouse door in over forty years, and no one had climbed up to light the lamp. Yet there it was, flashing. Mara grabbed her flashlight and her coat. She had to know who, or what, was up there.

Mara took the rowboat tied at the dock and pushed off toward the lighthouse rock. The water was calm and the oars barely splashed. Halfway across, the light flashed twice again, like it was answering her. She rowed faster.

Mara tied up the boat and climbed the slick rock steps to the door. It was already open a crack. She pushed it wide and called out. A voice from up the spiral stairs answered: 'You came. Finally, someone came.'

Mara climbed the stairs and found a girl about her own age, holding a big battery lamp. 'I'm Sol,' the girl said. 'My grandfather was the last keeper. I flash the light twice every night so ships know the rocks are still here. I never told anyone.'

Mara and Sol became a team. They cleaned up the old lamp room and asked the town for help fixing the real light. People who had been scared of the lighthouse for years finally came out to the rock. The mystery had a simple answer: a kid keeping ships safe. Now she had help, and the light never went dark again.