King Coal by Upton Sinclair

Hal proposed going to find Mrs. Zamboni at the place where she was staying; but Moylan interposed, objecting that the detectives would surely follow him. Even though they should all go out of the hotel at once, the one person the detective would surely stick to was the arch-rebel and troublemaker, Joe Smith. Finally they decided to bring Mrs. Zamboni to the room. Let her come with Mrs. Swajka or some other woman who spoke English, and go to the desk and ask for Mary Burke, explaining that Mary had borrowed money from her, and that she had to have it to pay the undertaker for the burial of her man. The hotel-clerk might not know who Mary Burke was; but the watchful "spotters" would gather about and listen, and if it was mentioned that Mary was from North Valley, someone would connect her with the kidnapped committee.

This was made clear to Rusick, who hurried off, and in the course of half an hour returned with the announcement that the women were on the way. A few minutes later came a tap on the door, and there stood the black-garbed old widow with her friend. She came in; and then came looks of dismay and horrified exclamations. Rusick was requesting her to give up her weeds to Joe Smith!