"But why? You steal a letter belonging to my guest, which you must have thought important, and then burn it unread. Do you expect me to understand your action? The thing seems purposeless."

"It isn't easy to explain, but I must try," she answered, nerving herself for an effort.

"That's obvious."

She hesitated a moment and then spoke bravely.

"I knew that something not right was going on at Appleyard."

"Ah! Did you know what it was?"

Elsie made a negative sign.

"I really didn't want to know; but I believed that the letter was dangerous. If I had read it, I might have felt forced to tell what I found out; so I put it straight into the fire."

"Knowing that its loss might embarra.s.s Williamson or me!"

"Yes," she said; "I thought of that. But I felt it would be safer for us all if I burned the paper."

"I suppose you understand that what you have admitted must make a difference? You have set yourself deliberately against me."

"If I had meant to injure you, I would have kept the letter; but I won't urge this. If Appleyard were yours, I would go away at once, but it is d.i.c.k's and he could not get on without my mother."

"Then you mean to stay and continue spying on my guests!"

"So long as no harm comes to d.i.c.k or Andrew, I shall leave you and your friends alone."

Staffer laughed.

"I'm afraid you're letting your imagination run away with you. What harm could come to either of them through me? But we'll say no more about it, just now."

He left her at the door and she went to her room and threw herself down on her couch, feeling rather limp, for the strain had told on her. Besides, her suspicions now were no longer vague. She had found a clue and she began to see where it led. Andrew was obviously watching the mouth of the Firth, while Rankine had some mysterious business farther west. Marshall thought it well that Andrew should know that the man with the red mustache had come from the suspected neighborhood late at night, in a salmon boat. The man had been at Appleyard, where he dropped an important letter; and Williamson and Staffer were in league with him. From all this it looked as if their business were treasonable.

This filled her with alarm, but she was glad she had told Staffer that she found the envelope. After all, he was her uncle and to have kept silence would have been treacherous; but the struggle between family obligations and her duty to the State got keener. It was unthinkable that she should spy upon a kinsman to whom she owed much; but would she not, in a sense, be an accomplice if she allowed him and the others to carry on their plots? This question, however, was dismissed for a time. There were other points to think about.

Did Staffer imagine she was in Andrew's confidence and secretly helping him; and had he believed her statement that she had destroyed the letter? If not, she was, perhaps, in some danger, because his laughing remark about her imagination had not been convincing. But, after all, what could he do? She could hardly be kidnapped and smuggled out of the country; and it was, of course, absurd to think of his attempting anything worse.

After a while she began to see her way. She would not watch her uncle, but if chance brought her clear proof that he was helping her country's enemies, she would see that he was stopped. This was a compromise that she suspected could hardly be justified; but the next decision was easier, because it had to do with those she loved. If Staffer or his friends plotted any harm to d.i.c.k or Andrew, she would remorselessly use every weapon she had against him.

Then she roused herself and bathed her face and hands, for she had felt some physical strain while she thrashed out the painful matter.

She would need calm and courage to meet Staffer as if nothing had happened, so that her mother might not suspect trouble. The part she had chosen was difficult, but she must play it out. When she went in to dinner she did not know whether she was relieved or not by Staffer's smile, but he talked to her with the suave good-humor he generally showed.

Two days after Elsie's talk with Jock Marshall, Andrew and Whitney were sitting in a Melrose hotel, when a postcard from Stranraer was brought to Andrew. There was a tarry fingermark at the bottom, alongside of the straggling signature, _J. Marshall_, Andrew read it aloud:

"As I'm away at the fishing, it might be weel if ye cam' home and lookit after the boat. Miss Elsie will give ye a bit message. I would not leave her until the tides get low."

Whitney smiled.

"You Scots are a remarkably cautious and capable lot," he said. "I can imagine the wrinkled old image writing this, with a wooden face and a chuckle inside. The meaning of the last sentence is cleverly ambiguous. I suppose the boat is quite all right?"

"Of course; no tide could hurt her."

"It's plain then that Marshall thinks you're wanted on Miss Woodhouse's account. I can have the motorcycle ready in five minutes, and if we pull out now we can be home soon after dark. Will you tell d.i.c.k?"

"No. We'll put him on the train, if there is one. Get that railway guide."

Whitney opened it.

"If you mean to see him off, you'll have to wait an hour; and, on the whole, I think you'd better. He seems to have made a number of acquaintances in the bar. Anyway, with this light frost, the roads will be good and hard."

d.i.c.k showed some unwillingness to leave the town, but Andrew was firm and put him on the train. When it started, he joined Whitney, who was waiting with the motorcycle.

The light was getting dim as they ran down the long dip to Hawick, though pale saffron, barred with leaden gray, shone above the western hills. When they swept down the last hill, frosty mist hung about the woolen mills in the hollow, and Whitney throttled his engine as they jolted past glimmering lights and half-seen houses.

"It doesn't look very cheerful for a fifty-mile run, but I suppose you want to get on," he remarked.

"Yes," said Andrew. "I hope d.i.c.k won't miss the train at one of the junctions, but he'll be all right if he reaches Carlisle. He can't well get into trouble at the place we stay at there."

The mist melted into the keen brightness of a frosty night as they climbed beside Teviot to the snow-sprinkled moors. Whitney's eyes were watering and his hands numb as they crossed the high watershed.

"We haven't lost much time, so far, but I suppose I'd better let her go her best," he said. "There oughtn't to be much traffic on the road."

Andrew nodded and pulled the rug tighter round him as the motorcycle leaped forward down the hill. He was eager to get back, for he felt anxious. It was not for nothing that Marshall had warned him that he was wanted.

There was moonlight in the shallow depression that led down from the summit, but soon the hilltops rose higher and they plunged into a dark glen. A glimmer of light flashed up to meet them, and as the side-car, rocking wildly, raced past the Mosspaul hotel, Andrew remembered what had happened there a few months previously. He had seen since then that d.i.c.k had not been in much danger when Staffer's car swerved; the risk of being struck down had been run by him only. Well, that did not matter much. If any one was threatened now, it was neither himself nor d.i.c.k, and it was horrible to feel that Elsie might be in some danger.

Whitney was driving recklessly fast, but Andrew frowned impatiently as he watched the hillsides unfold out of the dark and rush by while the throbbing of the engine filled the narrow glen.

They swung out at Ewes doors, leaning over hard as the car took the curve with an inch or two between the wheel and the drop to the burn.

Then the widening valley grew bright again and they raced up and down rolling hillsides, past scattered farms and white cothouses, until the lights of Langholm stretched across the hollow. Whitney slowed his engine here, but they narrowly escaped the wall, as they took the bridge below the town, and then sped on again furiously through the woods that line the brawling Esk.

Appleyard was reached in time for dinner, and Andrew was relieved to find that Staffer was not at home. Everything was as usual; it was difficult to imagine any cause for alarm; and he wondered whether he had been needlessly disturbed. After dinner, Mrs. Woodhouse took Whitney into the drawing-room and Andrew found Elsie knitting in a corner of the hall.

She looked up with a smile when he sat down near her.

"Haven't you come home earlier than you planned?" she asked.

Andrew studied her face. It was quiet and undisturbed, but he suspected a thoughtfulness that she meant to hide.

"Yes," he said. "I got a postcard from Marshall. He's at Stranraer and seemed to think I ought to look after the boat."

"The boat? But it's fine weather. Isn't she quite safe?"

"Oh, the tides are pretty high and run up the gutter fast."

Elsie counted her st.i.tches, and then gave him a quiet look.

"d.i.c.k was with you," she said; "so it couldn't have been on his account that you came back."