Emperor Chengwu's birthday fell on the ninth day of the tenth month. Every year around this time, the whole Capital City grew busy. The Grand Secretariat drew up the arrangements for the celebrations half a month in advance, the Ministry of Rites replaced all the palace lanterns with new ones, and the Imperial Kitchen prepared a menu that filled three whole sheets of paper, with eighteen varieties of pastries alone. Officials across the land sent people to deliver birthday gifts to the Capital City two months ahead of time. Their convoys stretched in long lines along the official roads, the escorting runners bundled in padded coats and hunched on horseback, breathing white clouds. The consorts and concubines of the harem rummaged through their belongings for talents to display: those who played the zither practiced, and those who embroidered stayed up late stitching. The princes prepared birthday gifts of their own. Every year, the Crown Prince gave his own calligraphy, a neatly copied scroll of the Classic of Filial Piety; the Second Prince had given inkstones and rare ancient books, always choosing something beyond reproach; the Third Prince usually offered an essay he had written himself, with properly composed birthday wishes along the lines of "May Father enjoy boundless longevity."
Only Qi Yu's gift was an unknown quantity every year. The longtime palace servants all remembered how, when the Fourth Prince was five or six, he had given his father a wooden box. He had picked up a few broken planks in the back courtyard of Yuning Hall and spent nearly half a month hammering away at them with a little hammer. The finished box was crooked, its lid misaligned with its body, leaving a gap on both the left and right when closed. Dark in color and rectangular in shape,