The Charwoman's Shadow by Lord Dunsany

Mirandola came back from the edge of the forest wondering, over wild heath to the garden. It had been her wont to know what her brother did, and even what he thought. But now he had some thought that she did not know, and it was at this that she wondered. She considered all the events that she thought might touch her brother; love first of all; and awhile she thought this was his motive, and then she thought it was something else. But she had not spoken with him long enough to guess that he went away so soon and so fast through the forest, with a packet of meat in his satchel, because he had lost what all material things have in attendance upon them whenever they face the light, and that he durst not show while other shadows were shorter his miserable strip of five feet of gloom. She had indeed heard tales of men who had sold their shadows, and knew that her brother had daily dealings with magic, but she had not guessed the fee that the Master took. She had told him not to bring gold. For what purpose then was his haste? Wondering, she returned to the garden.

Who could tell her? Only one. One only, amongst the few Mirandola knew, was able to work out such puzzles, and that was the good Father Joseph. And just as she thought of him she saw his plump shape coming smiling across the garden. It was by a path through the garden he was wont to come from his house whenever he came to see the Lord of the Tower; and he came now to help make ready for that event, now near at hand, of which all the neighbourhood talked, the visit of the serene and glorious hidalgo, the Duke of Shadow Valley.