One day, while studying at home, he noticed a magnificent steed lying among the weeds in his courtyard. It was dark-skinned with white markings, its tail hair uneven as if it had been scorched by fire. He drove it away, but it returned the next night, its origin a mystery. Cui Shusheng had a close friend serving as an official in Shanxi and wished to pay a visit, but lacked a mount. Thus, he saddled the black horse and set off for Shanxi, telling his family, "If the owner comes searching, tell them I borrowed it."

During the journey, the black horse moved like the wind, covering a hundred li in an instant. It never seemed to tire and ate very little. When it ran, its strength was inexhaustible; a journey of over a thousand li was completed in half a day. Upon arriving in Shanxi, Cui Shusheng led the horse through the marketplace, drawing crowds who gathered to marvel, sighing, "A fine horse, a truly fine horse."

The Prince of Jin heard of this and wished to purchase the black horse for a heavy sum. Cui Shusheng, fearing the rightful owner's wrath, dared not sell. Half a year passed without the owner appearing, so he finally sold the black horse to the Prince’s manor for eight hundred taels of silver, purchased a mule with the proceeds, and rode it back home.

Several years later, a Captain from the Prince of Jin’s retinue was ordered to conduct official business in Linqing County, riding that very black horse. As soon as they entered Linqing territory, the horse suddenly strained against the reins and bolted eastward. The Captain gave chase until he reached a residence owned by a man named Zeng. The black horse burst into the main hall and vanished without a trace.

The Captain searched the hall and saw on the wall a painting by Chen Zi'ang depicting a superb steed. The black horse in the painting was identical in bearing and size to his own mount. At the place where the painted horse's tail began, the canvas was singed by candlelight, leaving the hairs ragged and uneven.

The Captain paused for a moment, a sudden realization dawning: It seemed the black horse he rode was the very spirit of the painted horse given flesh.