'all the details of her coming into and going out of the palace -- on the night when she introduced herself in the character of an italian fortune teller -- you will tell her , that she may not doubt the correctness of my information ; that she had under her cloak a large white robe dotted with black tears , death 's heads , and crossbones -- for in case of a surprise , she was to pass for the phantom of the white sir who , as all the world knows , appears at the louvre every time any great event is impending . '