"You're a silly old-fashioned old dear," exclaimed the girl, "and I'm coming in. No, I'll keep the cab. We shall want it!"

"All right," said the Major, helping her to alight. "I tell you what.

We'll go into Harry Prankhurst's sitting-room. He's away for the week-end, anyway!"

He took Mary Trevert into a room off the hall and switched on the electric light. Then for the first time he saw how pale she looked.

"My dear," he said, "I know what an awful shock you've had...."

"You've heard about it?"

"I saw it in the Sunday papers. I was going to write to you."

"Euan," the girl began in a nervous, hasty way, "I have to go to Holland at once. There is not a moment to lose. I want you to help me get my pa.s.sport viseed."

"But, my dear girl," exclaimed the Major, aghast, "you can't go to Holland like this alone. Does your mother know about it?"

The girl shook her head.

"It's no good trying to stop me, Euan," she declared. "I mean to go, anyway. As a matter of fact, Mother doesn't know. I merely left word that I had gone to the Continent for a few days. n.o.body knows about Holland except you. And if you won't help me I suppose I shall have to go to Harry Tadworth at the Foreign Office. I came to you first because he's always so stuffy ..."

Euan MacTavish pushed the girl into a chair and gave her a cigarette. He lit it for her and took one himself. His pipe had vanished into his pocket.

"Of course, I'll help you," he said. "Now, tell me all about it!"

"Before ... this happened I had promised Hartley Parrish to marry him,"

began the girl. "The doctors say his nerves were wrong. I don't believe a word of it. He was full of the joy of life. He was very fond of me. He was always talking of what we should do when we were married. He never would have killed himself without some tremendously powerful motive.

Even then I can't believe it possible ..."

She made a little nervous gesture.

"After he ... did it," she went on, "I found this letter on his desk. It came to him from Holland. I mean to see the people who wrote it and discover if they can throw any light on ... on ... the affair ..."

She had taken from her m.u.f.f a letter, folded in four, written on paper of a curious dark slatey-blue colour.

"Won't you show me the letter?"

"You promise to say nothing about it to any one?"

He nodded.

"Of course."

Without a word the girl gave him the letter. With slow deliberation he unfolded it. The letter was typewritten and headed: "Elias van der Spyck & Co. General Importers, Rotterdam."

This was the letter:

ELIAS VAN DER SPYCK & CO.

GENERAL IMPORTERS ROTTERDAM Rotterdam 25th Nov.

_Codes_ A.B.C.

Liebler's

_Personal_ Dear Mr. Parrish,

Your favor of even date to hand and contents noted. The last delivery of steel was to time but we have had warning from the railway authorities that labour troubles at the docks are likely to delay future consignments. If you don't mind we should prefer to settle the question of future delivery by Nov. 27 as we have a board meeting on the 30th inst. While we fully appreciate your own difficulties with labour at home, you will understand that this is a question which we cannot afford to adjourn _sine die_.

Yours faithfully, pro ELIAS VAN DER SPYCK & CO.

The signature was illegible.

Euan MacTavish folded the letter again and handed it back to Mary.

"That doesn't take me any farther," he said. "What do the police think of it?"

"They haven't seen it," was the girl's reply. "I took it without them knowing. I mean to make my own investigations about this ..."

"But, my dear Mary," exclaimed the little Major in a shocked voice, "you can't do things that way! Don't you see you may be hindering the course of justice? The police may attach the greatest importance to this letter ..."

"You're quite right," retorted the girl, "they do!"

"Then why have you kept it from them?"

Mary Trevert dropped her eyes and a little band of crimson flushed into her cheeks.

"Because," she commenced, "because ... well, because they are trying to implicate a friend of mine ..."

The Major took the girl's hand.

"Mary," he said, "I've known you all your life. I've knocked about a good bit and know something of the world, I believe. Suppose you tell me all about it ..."

Mary Trevert hesitated. Then she said, her hands nervously toying with her m.u.f.f:

"We believe that Robin Greve--you know whom I mean--had a conversation with Hartley just before he ... he shot himself. That very afternoon Robin had asked me to marry him, but I told him about my engagement. He said some awful things about Hartley and rushed away. Ten minutes later Hartley Parrish committed suicide. And there _was_ some one talking to him in the library. Bude, the butler, heard the voices. This afternoon I went down to the library alone ... to see if I could discover anything likely to throw any light on poor Hartley's death. This was the only letter I could find. It was tucked away between two letter-trays. One tray fitted into the other, and this letter had slipped between. It seems to have been overlooked both by Mr. Parrish's secretary and the police ..."

"But I confess," argued the Major, "that I don't see how this letter, which appears to be a very ordinary business communication, implicates anybody at all. Why shouldn't the police see it?..."

"Because," said Mary, "directly after discovering it I found Bruce Wright, who used to be one of Mr. Parrish's private secretaries, hiding behind the curtains in the library. Now, Bruce Wright is a great friend of Robin Greve's, and I immediately suspected that Robin had sent him to Harkings, particularly as ..."

"As what?..."

"As he practically admitted to me, that he had come for a letter written on slatey-blue official-looking paper."

The girl held up the letter from Rotterdam.

"All this," the girl continued, "made me think that this letter must have had something to do with Hartley's death ..."

"Surely an additional reason for giving it to the police!..."