Behind the Bronze Door by William Le Queux

Doctor Johnson's optimism and words of encouragement set Cora's mind at rest to some extent, but she still felt anxious. She did not expect to be back in England for several weeks, and Johnson had told her that he intended to remain in Jersey about the same length of time. What, she asked herself, would happen meanwhile if she ignored the anonymous letter, as he advised? True, he had pointed out that the writer of the letter could have no desire to ruin her good name, and that she threatened only in order to terrorize her into paying the money. If she did not reply in the _Morning Post_, her persecutor would, he had assured her, write her another letter before taking any action. Indeed, he had declared that she would probably receive several letters before the writer attempted to carry out her threat.

"And remember," he had ended, "the more letters you get, and the more they threaten, the more evidence you possess to help to convict the villainess when she is arrested. Give her as much rope as possible, then strike hard and suddenly."