The key's label sent everyone toward the old shore. After the owner died, his nephew Idris tried it on three surviving boathouse doors without success. The family assumed the correct building had been demolished.
A neighbor remembered helping move a cupboard from a boathouse into the owner's kitchen. The key belonged to that cupboard, and the label retained the object's former location. Inside were household papers, not boating equipment.
Among them, Idris found the moving note: keep the old name or I will forget which key it is. His uncle had preserved a practical association rather than a precise description. The family search failed because they treated the label as a current address.
Idris relabeled the key for daily use but kept the old tag in the cupboard with the note. He could make the object easier to use without discarding the history that explained the mistake. The water had withdrawn, the cupboard had moved, and the word boathouse had stayed attached to a small piece of metal through both changes.