Still neglected by European-language research, the ‘Weft’ or ‘Apocrypha’ contain a wealth of unexploited data relevant to Chinese history in Late Antiquity and the Early Middle Ages. Sometimes ascribed to Confucius, these texts, whose Chinese name (wei 緯) denotes the crosswise threads of woven fabric, have long been perceived as arcane supplements to the ‘Classics’ (called jing 經, the lengthwise threads). Repeatedly prohibited and destroyed, they survive mainly as citations today. This paper focuses on one of them, anonymous and fragmentary, whose remnants mostly present extrapolations derived from observed phenomena interpreted as signs. By comparing the observed patterns to the typology of portents in the official monographs on celestial phenomena and the Five Agents of the era, the paper sheds light on the logic at work in the interpretative process.