English reader at level A2.1. Part of a series of readers ranging from level A1 to C2. In this story, Lena and her brother, Bill, spend a reluctant summer in Driftwood Bay with their grandfather, only to uncover a decades-old mystery hidden in a ruined lighthouse. Guided by a coded journal, they hunt for keys, dodge a shadowy figure, and learn their grandfather's secret past. The truth isn't treasure—but a powerful, hidden technology. Together, they choose to share the story.