The chief turned and summoned the other three men.

“You’d better break up,” he said.  “Two of you approach the place from one way—­two from another.  It’s now a quarter-past one—­you’ve plenty of time.  Stroll across the park to this spot—­I’ll join you by two o’clock.  I believe you can get light refreshments at this tea-house; get yourselves something, so as to look like mere loungers—­but keep your eyes open.”

“Do you want me, sir?” asked Chettle, eyeing the parcel with evident desire to know what mystery it concealed.

“No—­you go with Blindway,” answered the chief.  “He’ll tell you what’s happened.  I must join Mr. Allerdyke and Mr. Appleyard—­then we’ll come over to you.  Don’t take any notice of us.”

The four detectives went off into Hyde Park, and there separated in couples; the chief turned and went along the straight path which runs parallel with Bayswater Road just within the shrubberies of Kensington Gardens.  Presently he caught sight of Allerdyke and Appleyard, who occupied two chairs under a shady hawthorn tree, and he laid hold of another, dragged it to them, and sat down.  Each looked a silent inquiry, and the chief, with a smile, held up the parcel.

“Chettle and I,” he said, “have, in the presence of the manager and manageress of the Pompadour, made a thorough examination of the room and the belongings of the young lady who resides there under the name of Miss Slade.  There is not a jot or tittle of anything there to show that she is also Mrs. Marlow—­except one thing.  That, Mr. Allerdyke, is the all-important photograph of your cousin James, which is hanging, in a neat silver frame, over her mantelpiece.  What do you think of that, gentlemen?”

“Odd!” said Appleyard, after a moment’s reflective silence.

“Very queer!” said Allerdyke frowning.  “Very queer, indeed—­considering.”

“Queer and odd!” assented the chief.  “As to considering—­well, I don’t quite know what it is that we are considering.  If Miss Slade, alias Mrs. Marlow, is a member of the gang—­if there is one—­which killed and robbed James Allerdyke, it’s a decidedly odd and queer thing that she should frame the victim’s portrait and hang it where she’ll see it last thing at night and first thing in the morning.  Most extraordinary!  And it’s made me think a good deal.  I believe you once said, Mr. Allerdyke, that your cousin was a bit of a ladies’ man?”

“Bit that way inclined, was James,” replied Allerdyke laconically.  “Yes—­he fancied the ladies a bit, no doubt.  In quite a proper way, you know—­liked their society, and so on.”

“Just so!” assented the chief.  “Well, I wonder if he and Miss Slade, alias Mrs. Marlow, knew each other at all—­outside business?  But it’s not much use to speculate on that just now—­we’ve more urgent matters to attend to.  And first—­this!”

He had put a copy of a morning newspaper round the small brown paper parcel, and now took it off and showed the parcel itself to the two wondering men.  One of them at any rate uttered a sharp exclamation.