The Golden Bat by Fred M. White — Read

Ray turned over the photographs in his hand after the casual fashion of one who is not particularly interested. At the same time, he knew that his discovery was of the greatest possible importance. In the first place, he had identified Angela as the only child of Lord Barlington's unfortunate son, Charles, and, so far, he had not been wasting his time.

But for the present at any rate, he had no intention of telling Angela this, and that for many reasons. It was all very well to establish the secret of her birth and presently bring her in contact with her elderly relative, but it was not for that purpose that he had come into the tangle at all. In front of his love affairs he was a policeman, and before he could think of himself he had to place the duty which he owed to his employers. He knew perfectly well what effect this discovery would have upon Angela, and how difficult it would be for her to keep her joy and surprise a secret from the sharp eyes of Keen. And it was his intention to make use of Angela in bringing to justice one of the leading criminals of his day. And so far Ray was a long way from that.