Presently he glanced at his watch.

“I have to meet a man in Bloomsbury at six o’clock,” he said, “and it is now half-past five. Would you care to walk that far with me, darling?”

She answered that she would “adore to,” and so it came about that, on turning out of Russell Square, Preston pointed out a house to her on the opposite side of the street.

“That is a house you must often have heard about,” he said. “They call it the house with the bronze face. It is the headquarters of the famous Metropolitan Secret Agency.”

Yootha looked across at it with interest.

“What a horrible knocker!” she exclaimed. “Isn’t the face awful? I have heard Cora and the others speak about the place. She went there recently, as you know, to try to find out about Jessica, and she expects to hear soon. She described the knocker to me then. No wonder it has given the house a curious reputation—​I mean the stories that are told about it. But they are all nonsense, I suppose?” she ended, looking at Preston.

“Of course they must be, though the fact that Lord Froissart called there on the morning of the day he committed suicide has probably given the tales about the house a fresh lease of life. I can’t stand superstitious people, can you? I am glad you are not superstitious, dearest.”

Yootha laughed uneasily.

“It’s a gloomy, depressing-looking house, anyway,” she said, changing the subject as she glanced back at the door. “And it has a mysterious look. But I think a detective agency always sounds mysterious.”

“The people who run the Secret Agency must be extraordinarily clever,” Preston said. “The number of criminals they have brought to book is said to be very large, though the agency has not been in existence many years. I heard a rumor some days ago that they are now hot on the scent of the thieves who stole Mrs. Mervyn-Robertson’s jewels out of her safe during one of her evening parties.”