The Charwoman's Shadow by Lord Dunsany

Shadowless Ramon Alonzo went through the wood, as miserable in every glade and every shaft of sunlight as a man that crept through a city after being robbed of his raiment would feel whenever he came to a busy street. Shadowless he entered the house.

Now was a time for caution; his shadow gone, his eternal soul in danger, now was the time to watch the magician warily till an hour might come that should be favourable to a request. But every circumstance that should have urged delay drove the youth onward impetuously. How if he should die that night, and the doomed shadow get a throttle-grip immediately on his soul and drag it down to Hell! He durst not wait. He must win back that shadow.