The Umbrella Thief

Lena sells coffee at Elm Street station. She also sells umbrellas. When it rains, one umbrella disappears at half past three. The next morning it is back, with a note: "Borrowed with thanks." Who is it? Lena ties a bell to a pink umbrella. On a rainy day the bell rings. She follows the sound to the school gate. Old Mr. Petrov is giving umbrellas to children. Lena does not call the police. She makes a sign: "Free umbrellas. Bring back when dry."