For much of his education, Xue Longlong was silently accompanied from grade to grade, school to school, by a sealed Manila envelope stamped top secret. Stuffed inside were grades, test results, evaluations by fellow students and teachers, his Communist Party application and — most important for his job prospects — proof of his 2006 college degree.

Everyone in China who has been to high school has such a file. The files are irreplaceable histories of achievement and failure, the starting point for potential employers, government officials and others judging an individual’s worth. Often keys to the future, they are locked tight in government, school or workplace cabinets to eliminate any chance they might vanish.

But two years ago, Mr. Xue’s file did vanish. So did the files of at least 10 others, all 2006 college graduates with exemplary records, all from poor families living near this gritty north-central town on the wide banks of the Yellow River. Read in full.