Caleb Williams is hired as personal secretary to a British Squire, Fernando Falkland. In the course of his work he comes across a terrible secret from the Squire's past, and is sworn to secrecy. Falkland believes in the virtue of the upper classes and the villainy of the lower. He is uneasy in the power of a lowly servant and sets about persecuting Williams, leading to a series of adventures in an early thriller style.