For nine years, Elias Penn set his pocket watch by the sparrow. At eleven o'clock sharp the little brown bird dropped onto the third spoke of the fountain, cocked its head, and stayed exactly forty seconds. But this Tuesday the square was nearly empty when it should have been full of people and pigeons. Elias stood by the fountain, watch open in his hand, and waited. Eleven o'clock came. The sparrow did not.

Elias forgot about the empty square. He only cared about the sparrow. In nine years it had never missed a day. He climbed onto the fountain's edge and peered at the third spoke, looking for any sign of the little bird.