The Gilded Chair by Melville Davisson Post

That fantastic illusion, as of one come, after adventures, to the kingdom of some Magus, was preserved to the Duke of Dorset by the days that followed. He was for the most part wholly alone. He arose early, and lived the long day in the open; in the evening he dined with his host, and sat with him in the great library until midnight. At no other time did he see this curious old man.

He was distinctly conscious of two moods, contrary and opposite, changing with the day and night, like one going alternately into and out of the illusions of an opiate. Under the sun, in the dreamy haze of Indian summer, this beautiful château of yellow stone, set about with exquisite gardens, rimmed in the smoky distance with an amphitheater of mountains, was the handiwork of fairies, reset by enchantment from an Arabian tale. But at night, in the presence of Cyrus Childers, that mood vanished, as when one passing behind the staged scenery of a play meets there the carpenter.