The Indian Bangle by Fergus Hume — Read

As Mallow, at Drabble's elbow, stared at the demure little figure clothed in black, he realized that this was the fate controlling all things in connection with the affair he had in hand. Instantly he recognized in her the newspaper descriptions of the unknown housekeeper who had vanished so mysteriously and so completely from Athelstane Place. By name she had just been made known to him as Mrs. Arne, and he now learned that she and Madame Death-in-Life -- the notorious Madame Death-in-Life who was dreaded throughout Europe -- were one and the same person. He was face to face with the terrible woman with the terrible nick-name, the stormy petrel of Anarchy. At the mere rumour of her presence in their city, those in authority were wont suspiciously to look about them and doubly to safeguard their rulers. The Continental police would have given much to have had her safe in Monte Valerien, or Spandau, or Siberia.

Hitherto she had always evaded them at the last moment -- had thwarted their most zealous endeavours and carefully laid plans. She was Italian by birth, and had married an Englishman. She was now a widow and had made her husband's country her permanent home. As she sat before him now, so peacefully knitting, Mallow thought of Madame Defarge.