“I was going to suggest it,” answered Rayner.  “Let’s sit down and tell them all about it.”

The party of six went across to the quiet spot which the chief had indicated, and Fullaway and Appleyard obligingly arranged the chairs in a group.  Seated in the midst and quite conscious that she was the centre of attraction in several ways, Miss Slade began her explanation of the events and mysteries which had culminated in the recent sensational event.

“I daresay,” she said, looking round her, “that some of you know a great deal more about this affair than I do.  What I do know, however, is this—­the three men who have just been removed are without doubt the arch-spirits of the combination which robbed Miss Lennard, attempted to rob Mr. James Allerdyke, possibly murdered Mr. James Allerdyke, and certainly murdered Lydenberg, Lisette Beaurepaire, and Ebers.  Van Koon is an American crook, whose real name is Vankin; Merrifield, as you know, is Mr. Delkin’s secretary; the other man is one Otto Schmall, a German chemist, and a most remarkably clever person, who has a shop and a chemical manufactory in Whitechapel.  He’s an expert in poison—­and I think you will have some interesting matters to deal with when you come to tackle his share.  Well, that’s plain fact; and now you want to know how I—­and Mr. Rayner—­found all this out.”

“Chiefly you,” murmured Rayner, “chiefly you!”

“You had better let your minds go back to the morning of the 13th May last,” continued Miss Slade, paying no apparent heed to this interruption.  “On that morning I arrived at Mr. Fullaway’s office at my usual time, ten o’clock, to find that Mr. Fullaway had departed suddenly, earlier in the morning, for Hull.  I at once guessed why he had gone—­I knew that Mr. James Allerdyke, in charge of the Princess Nastirsevitch’s jewels, was to have landed at Hull the night before, and I concluded that Mr. Fullaway had set off to meet him.  But Mr. Fullaway has a bad habit of leaving letters and telegrams lying about, for any one to see, and within a few minutes I found on his desk a telegram from Mr. Marshall Allerdyke, dispatched early that morning from Hull, saying that his cousin had died suddenly during the night.  That, of course, definitely explained Mr. Fullaway’s departure, and it also made me wonder, knowing all I did know, if the jewels were safe.

“This, I repeat, was about ten to half-past ten o’clock.  About twelve o’clock of that morning, the 13th, Mr. Van Koon, whom I knew as a resident in the hotel, and a frequent caller on Mr. Fullaway, came in.  He wanted Mr. Fullaway to cash a cheque for him.  I told him that I could do that, and I took his cheque, wrote out one of my own and went up town to Parr’s Bank, at the bottom of St. Martin’s Lane, to get the cash for him.  Mr. Van Koon stayed in the office, reading a bundle of American newspapers which had just been delivered.  I was away from the office perhaps forty minutes or so; when I returned he was still there.  I gave him the money; he thanked me, and went away.