The envelope showed up on a Tuesday, sea-blue and soft at the corners. The handwriting belonged to Theo, Mara's best friend from when she was eleven. Twenty years of silence, and now one line inside: "I found the map of Saltreach in my mom's attic. The lighthouse is still unfinished. Want to build it?" Mara sat down hard and read it three more times.

Mara typed a careful reply asking the question that had haunted her for years: why did Theo's family leave Saltreach overnight, without a word, the summer they were eleven? She hit send before she lost her nerve. An hour later three dots appeared. Then: "Come to Saltreach. I'll tell you everything in person. I promise."

Mara drove out the next day. Theo met her at a small cafe and slid a faded photo across the table: his father, in a hospital bed, the same summer they were kids. "He got sick fast. We left at night because he didn't want anyone to see him go," Theo said. "I wanted to tell you. I was eleven and terrified."

Mara reached across the table and took Theo's hand. "I'm not angry. I just missed you," she said. He let out a long breath, like he'd carried that weight for twenty years. "So," he said, sliding the old map out of his bag, "about that lighthouse." Mara smiled. "Let's go look at it right now."

They walked to the cliff that afternoon and stood over the old foundation. Mara knelt and brushed dirt off the first stone. "We start here," she said. They built it over one long summer, the map taped to a post for reference. The night the lamp lit, Theo whispered, "Took us long enough." Mara just grinned.