On Tuesday, October 12, 1954, Pierre Vernier, a teacher in a Paris lycee, begins writing what he wants to be the complete record of his life, his students, and his fellow teachers. He begins by meticulously documenting the facts he already knows about his students - their names, ages, the relationships among them, and the books they're studying. Then he enlists his nephew - a student in his class - to report on the private lives of the other boys. He then studies the school manuals for every subject and class these students are taking - for to record all reality, he must know all that has passed, is passing, and will pass through his students' minds.
But Vernier finds that the core of what he actually knows is useless unless he can spin around it a concentric web of larger suppositions, endowed with varying "degrees" of truth. Relying on his nephew's information, he writes Part Two of his manuscript as if it were being written by his nephew. Finally, in Part Three, the raw material of life overwhelms his delicate literary structure, thus exposing the impossibility of his obsession and the damaging effect this obsession has on both himself and those who surround him.