King Coal by Upton Sinclair

Hal stood and watched the portly figure until it disappeared; then he turned back and passed the three detectives, who stopped. He stared at them, but made no sign, nor did they. Some twenty feet behind him, they fell in and followed as before.

Judge Denton had suggested consulting a policeman; and suddenly Hal noticed that he was passing the City Hall, and it occurred to him that this matter of his being shadowed might properly be brought to the attention of the mayor of Pedro. He wondered what the chief magistrate of such a "hell of a town" might be like; after due inquiry, he found himself in the office of Mr. Ezra Perkins, a mild-mannered little gentleman who had been in the undertaking-business, before he became a figurehead for the so-called "Democratic" machine.