"He is either alone or I am with him."
"There are two keys, I believe; can the safe be opened without the production of both?"
"One is sufficient, but you must have the 'word.'"
"The 'word,' madam?"
"Yes, it is a French idea, I think, and Milner had to pay money to use it. There are three small discs, each surrounded with the letters of the alphabet, on the door of the safe, and the diminutive hands on the discs have to be set to a certain word before the keys are of any use. When the diamond disappeared the word was 'war;' one hand had to be pointing to 'w,' the second to 'a,' and the third to 'r.' When the safe is locked the hands on the discs are, of course, turned to any of the letters of the alphabet but the right ones. Although you held the key, it would be perfectly useless to you without knowing the exact word, and you might go through the whole dictionary without discovering it."
"Have you any system in changing the 'word?'"
"I generally alter it every month; this is effected through the clock-work on the back of the lid—but although I always acquaint my husband with the secret it soon escapes his memory, and he has invariably to come to me for the information."
"Can the diamond have fallen into wrong hands?"
"That will be for you to discover; there is one thing certain, it is not in the safe nor in Lord B—— 's possession. My maid and I have made a thorough search."
"Then the loss of this stone is well known in your ladyship's household?"