"I should prefer to suspend judgment until we've seen the letter, Mr.

Greve," said the detective bluntly. "We must get it from Jeekes. In the meantime, what makes you think that the murderer (to follow up your theory) was conversant with the lay of the land at Harkings?"

"Because," answered Robin, "the murderer left no tracks on the gra.s.s or flower-beds. He stuck to the hard gravel path throughout. That path, which runs from the drive through the rosery to the gravel path round the house just under the library window, is precious hard to find in the dark, especially where it leaves the drive, as at the outset it is a mere thread between the rhododendron bushes. And, as I know from experience, unless you are acquainted with the turns in the path, it is very easy to get off it in the dark, especially in the rosery, and go blundering on to the flower-beds. And I'll tell you something else about the murderer. He--or she--was of small stature--not much above five foot six in height. The upward diagonal course of the bullet through Parrish's heart shows that ..."

Mr. Manderton shook his head dubiously.

"Very ingenious," he commented. "But you go rather fast, Mr. Greve. We must test your theory link by link. There may be an explanation for Jeekes's apparently inexplicable lie to the young lady. Let's see him and hear what he says. The grounds at Harkings must be searched for this second bullet, if second bullet there is, the mark on the tree examined by an expert. And since two bullets argue two pistols in this case, let us see what result we get from our enquiries as to where Mr. Parrish bought his pistol. He may have had two pistols ..."

"If Parrish used a silencer," remarked Robin, quite undisconcerted by the other's lack of enthusiasm, "and my theory that two shots were fired is correct, there must have been two reports, a loud one and a m.u.f.fled one. Miss Trevert heard one report, as we know. Did she hear a second?"

"She said nothing about it," remarked the detective.

"She was probably asked nothing about it. But we can get this point cleared up at once. There's the telephone. Ring up Harkings and ask her now."

"Why not?" said Mr. Manderton and moved to the telephone.

There is little delay on the long-distance lines on a Sunday evening, and the call to Harkins came through almost at once. Bude answered the telephone at Harkings. Manderton asked for Miss Trevert. The butler replied that Miss Trevert was no longer at Harkings. She had gone to the Continent for a few days.

This plain statement, retailed in the fortissimo voice which Bude reserved for use on the telephone, produced a remarkable effect on the detective. He grew red in the face.

"What's that?" he cried a.s.sertively. "Gone to the Continent? I should have been told about this. Why wasn't I informed? What part of the Continent has she gone to?"

Mr. Manderton's questions, rapped out with a rasping vigour that recalled a machine-gun firing, brought Robin to his feet in an instant.

He crossed over to the desk on which the telephone stood.

Manderton placed one big palm over the transmitter and turned to Robin.

"She's gone to the Continent and left no address," he said quickly.

"Ask him if Lady Margaret is there," suggested Robin.

Mr. Manderton spoke into the telephone again. Lady Margaret had gone to bed, Bude answered, and her ladyship was much put out by Miss Trevert gallivanting off like that by herself with only a scribbled note left to say that she had gone.

Had Bude got the note?

No, Mr. Manderton, sir, he had not. But Lady Margaret had shown it to him. It had simply stated that Miss Trevert had gone off to the Continent and would be back in a few days.

Again the detective turned to Robin at his elbow.

"These country b.u.mpkins!" he said savagely. "I must go to the Yard and get Humphries on the 'phone. He may have telegraphed me about it. You stay here and I'll ring you later if there's any news. What do you make of it, Mr. Greve?"

"It beats me," was Robin's rueful comment. "And what about the inquest?

It's for Tuesday, isn't it? Miss Trevert will have to give evidence, I take it?..."

"Oh," said Mr. Manderton, picking up his hat and speaking in an offhand way, "I'm getting _that_ adjourned for a week!"

"The inquest adjourned! Why?"

There was a twinkle in the detective's eye as he replied.

"I thought, maybe, I might get further evidence ..."

Robin caught the expression and smiled.

"And when did you come to this decision, may I ask?"

"After our little experiment in the garden this morning," was the detective's prompt reply.

Robin looked at him fixedly.

"But, see here," he said, "apparently it was to the deductions you formed from the result of that experiment that I owe the attentions of your colleagues who have been hanging round the house all day. And yet you now come to me and invite my a.s.sistance. Mr. Manderton, I don't get it at all!"

"Mr. Greve," replied the detective, "Miss Trevert tried to shield you.

That made me suspicious. You tried to force my investigations into an entirely new path. That deepened my suspicions. I believed it to be my duty to ascertain your movements after leaving Harkings. But then I heard Jeekes make an apparently gratuitously false statement to Miss Trevert with an implication against you. That, to some extent, cleared you in my eyes. I say 'to some extent' because I will not deny that I thought I might be taking a risk in coming to you like this. You see I am frank!..."

The smile had left Greve's face and he looked rather grim.

"You're pretty deep, aren't you?" was his brief comment.

CHAPTER XX

THE CODE KING

Major Euan MacTavish was packing. A heavy and well-worn leather portmanteau, much adorned with foreign luggage labels, stood in the centre of the floor. From a litter of objects piled up on a side table the Major was transferring to it various brown-paper packages which he checked by a list in his hand.

The Major always packed for himself. He packed with the neatness and rapidity derived from long experience of travel. As a matter of fact, he could not afford a manservant any more than he could allow himself quarters more luxurious than the rather grimy bedroom in Bury Street which housed him during his transient appearances in town. The remuneration doled out by the Foreign Office to the quiet and un.o.btrusive gentlemen known as King's messengers is, in point of fact, out of all proportion to the prestige and glamour surrounding the silver greyhound badge, an example of which was tucked away in a pocket of the Major's blue serge jacket hanging over the back of a chair.

"Let's see," said the Major, addressing a large brown-paper covered package standing in the corner of the room, "you're the bird-cage for Lady Sylvia at The Hague. Two pounds of candles for Mrs. Harry Deepdale at Berlin; the razor blades for Sir Archibald at Prague; the Teddy bear for Marjorie; polo-b.a.l.l.s for the Hussars at Constantinople--there! I think that's the lot! Hullo, hullo, who the devil's that?"

With a groaning of wires a jangling bell tinkled through the hall (the Major's bedroom was on the ground floor). Sims, the aged ex-butler, who, with his wife, "did for" his lodgers in more ways than one, was out and the single servant-maid had her Sunday off. Euan MacTavish glanced at his wrist watch. It showed the hour to be ten minutes past nine. A flowered silk smoking-coat over his evening clothes and a briar pipe in his mouth, he went out into the hall and opened the front door.

It was a drenching night. The lamps from a taxi which throbbed dully in the street outside the house threw a gleaming band of light on the shining pavement. At the door stood a taxi-driver.

"There's a lady asking for Major MacTavish," he said, pointing at the cab. The Major stepped across to the cab and opened the door.

"Oh, Euan," said a girl's voice, "how lucky I am to catch you!"

"Why, Mary," exclaimed the Major, "what on earth brings you round to me on a night like this? I only came up from the country this afternoon and I'm off for Constantinople in the morning!"

"Euan," said Mary Trevert, "I want to talk to you. Where can we talk?"

The Major raised his eyebrows. He was a little man with grizzled hair and finely cut, rather sharp features.

"Well," he remarked, "there's not a soul in the house, and I've only got a bedroom here. Though we're cousins, Mary, my dear, I don't know that you ought to...."