But that manner suddenly changed as he came face to face with the lady in question.

Not that it lost its respect, but that it betrayed an astonishment of a more pronounced character than was usually indulged in by this experienced detective.

The lady before him was one well known to him; in fact, almost an associate of his in certain bygone matters; in other words, none other than that most reputable of ladies, Miss Amelia Butterworth of Gramercy Park..