When all the children of the village come down with a mysterious illness during the silkworm harvest, Number Ten Ox, stout of heart though modest of intellectual attainment, goes on a mission to the big city to hire a sage, armed with his Auntie Hua's small fortune, five thousand copper cash. Under the sign of the half-closed eye he finds the disreputable Master Li, a scholar with a slight flaw in his character. The solution of the riddle of the sleeping children will require the solving of a literal, ancient riddle, the sacrifice of a miser's fortune in pearls and jade, and an investigation into the whereabouts of an immortal's heart, before the birds can fly once more.