About ten o'clock on a fine evening towards the end of June, some six weeks after the incident described in the last chapter, Merriman formed one of a group of young men seated round the open window of the smoking room in the Rovers' Club in Cranbourne Street. They had dined together, and were enjoying a slack hour and a little desultory conversation before moving on, some to catch trains to the suburbs, some to their chambers in town, and others to round off the evening with some livelier form of amusement. The Rovers had premises on the fourth floor of a large building near the Hippodrome. Its membership consisted principally of business and professional men, but there was also a sprinkling of members of Parliament, political secretaries, and minor government officials, who, though its position was not ideal, were attracted to it because of the moderation of its subscription and the excellence of its cuisine.

The evening was calm, and the sounds from the street below seemed to float up lazily to the little group in the open window, as the smoke of their pipes and cigars floated up lazily to the ceiling above. The gentle hum of the traffic made a pleasant accompaniment to their conversation, as the holding down of a soft pedal fills in and supports dreamy organ music. But for the six young men in the bow window the room was untenanted, save for a waiter who had just brought some fresh drinks, and who was now clearing away empty glasses from an adjoining table.

The talk had turned on foreign travel, and more than one member had related experiences which he had undergone while abroad. Merriman was tired and had been rather silent, but it was suddenly borne in on him that it was his duty, as one of the hosts of the evening, to contribute somewhat more fully towards the conversation. He determined to relate his little adventure at the sawmill of the Pit-Prop Syndicate. He therefore lit a fresh cigar, and began to speak.

“Any of you fellows know the country just south of Bordeaux?” he asked, and, as no one responded, he went on: “I know it a bit, for I have to go through it every year on my trip round the wine exporters. This year a rather queer thing happened when I was about half an hour's run from Bordeaux; absolutely a trivial thing and of no importance, you understand, but it puzzled me. Maybe some of you could throw some light on it?”

“Proceed, my dear sir, with your trivial narrative,” invited Jelfs, a man sitting at one end of the group. “We shall give it the weighty consideration which it doubtless deserves.”

Jelfs was a stockbroker and the professional wit of the party. He was a good soul, but boring. Merriman took no notice of the interruption.

“It was between five and six in the evening,” he went on, and he told in some detail of his day's run, culminating in his visit to the sawmill and his discovery of the alteration in the number of the lorry. He gave the facts exactly as they had occurred, with the single exception that he made no mention of his meeting with Madeleine Coburn.

“And what happened?” asked Drake, another of the men, when he had finished.

“Nothing more happened,” Merriman returned. “The manager came and gave me some petrol, and I cleared out. The point is, why should that number plate have been changed?”

Jelfs fixed his eyes on the speaker, and gave the little sidelong nod which indicated to the others that another joke was about to be perpetrated.

“You say,” he asked impressively, “that the lorry was at first 4 and then 3. Are you sure you haven't made a mistake of 41?”

“How do you mean?”

“I mean that it's a common enough phenomenon for a No. 4 lorry to change, after lunch, let us say, into No. 44. Are you sure it wasn't 44?”

Merriman joined in the laughter against him.

“It wasn't forty-anything, you old blighter,” he said good-humoredly. “It was 4 on the road, and 3 at the mill, and I'm as sure of it as that you're an amiable imbecile.”

“Inconclusive,” murmured Jelfs, “entirely inconclusive. But,” he persisted, “you must not hold back material evidence. You haven't told us yet what you had at lunch.”

“Oh, stow it, Jelfs,” said Hilliard, a thin-faced, eager-looking young man who had not yet spoken. “Have you no theory yourself, Merriman?”

“None. I was completely puzzled. I would have mentioned it before, only it seemed to be making a mountain out of nothing.”

“I think Jelfs' question should be answered, you know,” Drake said critically, and after some more good-natured chaff the subject dropped.

Shortly after one of the men had to leave to catch his train, and the party broke up. As they left the building Merriman found Hilliard at his elbow.

“Are you walking?” the latter queried. “If so I'll come along.”

Claud Hilliard was the son of a clergyman in the Midlands, a keen, not to say brilliant student who had passed through both school and college with distinction, and was already at the age of eight-and-twenty making a name for himself on the headquarters staff of the Customs Department. His thin, eager face, with its hooked nose, pale blue eyes and light, rather untidy-looking hair, formed a true index of his nimble, somewhat speculative mind. What he did, he did with his might. He was keenly interested in whatever he took up, showing a tendency, indeed, to ride his hobbies to death. He had a particular penchant for puzzles of all kinds, and many a knotty problem brought to him as a last court of appeal received a surprisingly rapid and complete solution. His detractors, while admitting his ingenuity and the almost uncanny rapidity with which he seized on the essential facts of a case, said he was lacking in staying power, but if this were so, he had not as yet shown signs of it.

He and Merriman had first met on business, when Hilliard was sent to the wine merchants on some matter of Customs. The acquaintanceship thus formed had ripened into a mild friendship, though the two had not seen a great deal of each other.

They passed up Coventry Street and across the Circus into Piccadilly. Hilliard had a flat in a side street off Knightsbridge, while Merriman lived farther west in Kensington. At the door of the flat Hilliard stopped.

“Come in for a last drink, won't you?” he invited. “It's ages since you've been here.”

Merriman agreed, and soon the two friends were seated at another open window in the small but comfortable sitting-room of the flat.

They chatted for some time, and then Hilliard turned the conversation to the story Merriman had told in the club.

“You know,” he said, knocking the ash carefully off his cigar, “I was rather interested in that tale of yours. It's quite an intriguing little mystery. I suppose it's not possible that you could have made a mistake about those numbers?”

Merriman laughed.

“I'm not exactly infallible, and I have, once or twice in my life, made mistakes. But I don't think I made one this time. You see, the only question is the number at the bridge. The number at the mill is certain. My attention was drawn to it, and I looked at it too often for there to be the slightest doubt. It was No. 3 as certainly as I'm alive. But the number at the bridge is different. There was nothing to draw my attention to it, and I only glanced at it casually. I would say that I was mistaken about it only for one thing. It was a black figure on a polished brass ground, and I particularly remarked that the black lines were very wide, leaving an unusually small brass triangle in the center. If I noticed that, it must have been a 4.”

Hilliard nodded.

“Pretty conclusive, I should say.” He paused for a few moments, then moved a little irresolutely. “Don't think me impertinent, old man,” he went on with a sidelong glance, “but I imagined from your manner you were holding something back. Is there more in the story than you told?”

It was now Merriman's turn to hesitate. Although Madeleine Coburn had been in his thoughts more or less continuously since he returned to town, he had never mentioned her name, and he was not sure that he wanted to now.

“Sorry I spoke, old man,” Hilliard went on. “Don't mind answering.”

Merriman came to a decision.

“Not at all” he answered slowly. “I'm a fool to make any mystery of it. I'll tell you. There is a girl there, the manager's daughter. I met her in the lane when I was following the lorry, and asked her about petrol. She was frightfully decent; came back with me and told her father what I wanted, and all that. But, Hilliard, here's the point. She knew! There's something, and she knows it too. She got quite scared when that driver fixed me with his eyes, and tried to get me away, and she was quite unmistakably relieved when the incident passed. Then later her father suggested she should see me to the road, and on the way I mentioned the thing—said I was afraid I had upset the driver somehow—and she got embarrassed at once, told me the man was shell-shocked, implying that he was queer, and switched off on to another subject so pointedly I had to let it go at that.”

Hilliard's eyes glistened.

“Quite a good little mystery,” he said. “I suppose the man couldn't have been a relation, or even her fiancee?”

“That occurred to me, and it is possible. But I don't think so. I believe she wanted to try to account for his manner, so as to prevent my smelling a rat.”

“And she did not account for it?”

“Perhaps she did, but again I don't think so. I have a pretty good knowledge of shell-shock, as you know, and it didn't look like it to me. I don't suggest she wasn't speaking the truth. I mean that this particular action didn't seem to be so caused.”

There was silence for a moment, and then Merriman continued:

“There was another thing which might bear in the same direction, or again it may only be my imagination—I'm not sure of it. I told you the manager appeared just in the middle of the little scene, but I forgot to tell you that the driver went up to him and said something in a low tone, and the manager started and looked at me and seemed annoyed. But it was very slight and only for a second; I would have noticed nothing only for what went before. He was quite polite and friendly immediately after, and I may have been mistaken and imagined the whole thing.”

“But it works in,” Hilliard commented. “If the driver saw what you were looking at and your expression, he would naturally guess what you had noticed, and he would warn his boss that you had tumbled to it. The manager would look surprised and annoyed for a moment, then he would see he must divert your suspicion, and talk to you as if nothing had happened.”

“Quite. That's just what I thought. But again, I may have been mistaken.”

They continued discussing the matter for some time longer, and then the conversation turned into other channels. Finally the clocks chiming midnight aroused Merriman, and he got up and said he must be going.

Three days later he had a note from Hilliard.

“Come in tonight about ten if you are doing nothing,” it read. “I have a scheme on, and I hope you'll join in with me. Tell you when I see you.”

It happened that Merriman was not engaged that evening, and shortly after ten the two men were occupying the same arm-chairs at the same open window, their glasses within easy reach and their cigars well under way.

“And what is your great idea?” Merriman asked when they had conversed for a few moments. “If it's as good as your cigars, I'm on.”

Hilliard moved nervously, as if he found a difficulty in replying. Merriman could see that he was excited, and his own interest quickened.

“It's about that tale of yours,” Hilliard said at length. “I've been thinking it over.”

He paused as if in doubt. Merriman felt like Alice when she had heard the mock-turtle's story, but he waited in silence, and presently Hilliard went on.

“You told it with a certain amount of hesitation,” he said. “You suggested you might be mistaken in thinking there was anything in it. Now I'm going to make a SUGGESTION with even more hesitation, for it's ten times wilder than yours, and there is simply nothing to back it up. But here goes all the same.”

His indecision had passed now, and he went on fluently and with a certain excitement.

“Here you have a trade with something fishy about it. Perhaps you think that's putting it too strongly; if so, let us say there is something peculiar about it; something, at all events, to call one's attention to it, as being in some way out of the common. And when we do think about it, what's the first thing we discover?”

Hilliard looked inquiringly at his friend. The latter sat listening carefully, but did not speak, and Hilliard answered his own question.

“Why, that it's an export trade from France to England—an export trade only, mind you. As far as you learned, these people's boat runs the pit-props to England, but carries nothing back. Isn't that so?”

“They didn't mention return cargoes,” Merriman answered, “but that doesn't mean there aren't any. I did not go into the thing exhaustively.”

“But what could there be? What possible thing could be shipped in bulk from this country to the middle of a wood near Bordeaux? Something, mind you, that you, there at the very place, didn't see. Can you think of anything?”

“Not at the moment. But I don't see what that has to do with it.”

“Quite possibly nothing, and yet it's an INTERESTING point.”

“Don't see it.”

“Well, look here. I've been making inquiries, and I find most of our pit-props come from Norway and the Baltic. But the ships that bring them don't go back empty. They carry coal. Now do you see?”

It was becoming evident that Hilliard was talking of something quite definite, and Merriman's interest increased still further.

“I daresay I'm a frightful ass,” he said, “but I'm blessed if I know what you're driving at.”

“Costs,” Hilliard returned. “Look at it from the point of view of costs. Timber in Norway is as plentiful and as cheap to cut as in the Landes, indeed, possibly cheaper, for there is water there available for power. But your freight will be much less if you can get a return cargo. Therefore, a priori, it should be cheaper to bring props from Norway than from France. Do you follow me so far?”

Merriman nodded.

“If it costs the same amount to cut the props at each place,” Hilliard resumed, “and the Norwegian freight is lower, the Norwegian props must be cheaper in England. How then do your friends make it pay?”

“Methods more up to date perhaps. Things looked efficient, and that manager seemed pretty wide-awake.”

Hilliard shook his head.

“Perhaps, but I doubt it. I don't think you have much to teach the Norwegians about the export of timber. Mind you, it may be all right, but it seems to me a question if the Bordeaux people have a paying trade.”

Merriman was puzzled.

“But it must pay or they wouldn't go on with it. Mr. Coburn said it was paying well enough.”

Hilliard bent forward eagerly.

“Of course he would say so,” he cried. “Don't you see that his saying so is in itself suspicious? Why should he want to tell you that if there was nothing to make you doubt it?”

“There is nothing to make me doubt it. See here, Hilliard, I don't for the life of me know what you're getting at. For the Lord's sake explain yourself.”

“Ah,” Hilliard returned with a smile, “you see you weren't brought up in the Customs. Do you know, Merriman, that the thing of all others we're keenest on is an import trade that doesn't pay?” He paused a moment, then added slowly: “Because if a trade which doesn't pay is continued, there must be something else to make it pay. Just think, Merriman. What would make a trade from France to this country pay?”

Merriman gasped.

“By Jove, Hilliard! You mean smuggling?”

Hilliard laughed delightedly.

“Of course I mean smuggling, what else?”

He waited for the idea to sink into his companion's brain, and then went on:

“And now another thing. Bordeaux, as no one knows better than yourself, is just the center of the brandy district. You see what I'm getting at. My department would naturally be interested in a mysterious trade from the Bordeaux district. You accidentally find one. See? Now what do you think of it?”

“I don't think much of it,” Merriman answered sharply, while a wave of unreasoning anger passed over him. The SUGGESTION annoyed him unaccountably. The vision of Madeleine Coburn's clear, honest eyes returned forcibly to his recollection. “I'm afraid you're out of it this time. If you had seen Miss Coburn you would have known she is not the sort of girl to lend herself to anything of that kind.”

Hilliard eyed his friend narrowly and with some surprise, but he only said:

“You think not? Well, perhaps you are right. You've seen her and I haven't. But those two points are at least INTERESTING—the changing of the numbers and the absence of a return trade.”

“I don't believe there's anything in it.”

“Probably you're right, but the idea interests me. I was going to make a proposal, but I expect now you won't agree to it.”

Merriman's momentary annoyance was subsiding.

“Let's hear it anyway, old man,” he said in conciliatory tones.

“You get your holidays shortly, don't you?”

“Monday week. My partner is away now, but he'll be back on Wednesday. I go next.”

“I thought so. I'm going on mine next week—taking the motor launch, you know. I had made plans for the Riviera—to go by the Seine, and from there by canal to the Rhone and out at Marseilles. Higginson was coming with me, but as you know he's crocked up and won't be out of bed for a month. My proposal is that you come in his place, and that instead of crossing France in the orthodox way by the Seine, we try to work through from Bordeaux by the Garonne. I don't know if we can do it, but it would be rather fun trying. But anyway the point would be that we should pay a call at your sawmill on the way, and see if we can learn anything more about the lorry numbers. What do you say?”

“Sounds jolly fascinating.” Merriman had quite recovered his good humor. “But I'm not a yachtsman. I know nothing about the business.”

“Pooh! What do you want to know? We're not sailing, and motoring through these rivers and canals is great sport. And then we can go on to Monte and any of those places you like. I've done it before and had no end of a good time. What do you say? Are you on?”

“It's jolly decent of you, I'm sure, Hilliard. If you think you can put up with a hopeless landlubber, I'm certainly on.”

Merriman was surprised to find how much he was thrilled by the proposal. He enjoyed boating, though only very mildly, and it was certainly not the prospect of endless journeyings along the canals and rivers of France that attracted him. Still less was it the sea, of which he hated the motion. Nor was it the question of the lorry numbers. He was puzzled and interested in the affair, and he would like to know the solution, but his curiosity was not desperately keen, and he did not feel like taking a great deal of trouble to satisfy it. At all events he was not going to do any spying, if that was what Hilliard wanted, for he did not for a moment accept that smuggling theory. But when they were in the neighborhood he supposed it would be permissible to call and see the Coburns. Miss Coburn had seemed lonely. It would be decent to try to cheer her up. They might invite her on board, and have tea and perhaps a run up the river. He seemed to visualize the launch moving easily between the tree-clad banks, Hilliard attending to the engine and steering, he and the brown-eyed girl in the taffrail, or the cockpit, or the well, or whatever you sat in on a motor boat. He pictured a gloriously sunny afternoon, warm and delightful, with just enough air made by the movement to prevent it being too hot. It would...

Hilliard's voice broke in on his thoughts, and he realized his friend had been speaking for some time.

“She's over-engined, if anything,” he was saying, “but that's all to the good for emergencies. I got fifteen knots out of her once, but she averages about twelve. And good in a sea-way, too. For her size, as dry a boat as ever I was in.”

“What size is she?” asked Merriman.

“Thirty feet, eight feet beam, draws two feet ten. She'll go down any of the French canals. Two four-cylinder engines, either of which will run her. Engines and wheel amidships, cabin aft, decked over. Oh, she's a beauty. You'll like her, I can tell you.”

“But do you mean to tell me you would cross the Bay of Biscay in a boat that size?”

“The Bay's maligned. I've been across it six times and it was only rough once. Of course, I'd keep near the coast and run for shelter if it came on to blow. You need not worry. She's as safe as a house.”

“I'm not worrying about her going to the bottom,” Merriman answered. “It's much worse than that. The fact is,” he went on in a burst of confidence, “I can't stand the motion. I'm ill all the time. Couldn't I join you later?”

Hilliard nodded.

“I had that in my mind, but I didn't like to suggest it. As a matter of fact it would suit me better. You see, I go on my holidays a week earlier than you. I don't want to hang about all that time waiting for you. I'll get a man and take the boat over to Bordeaux, send the man home, and you can come overland and join me there. How would that suit you?”

“A1, Hilliard. Nothing could be better.”

They continued discussing details for the best part of an hour, and when Merriman left for home it had been arranged that he should follow Hilliard by the night train from Charing Cross on the following Monday week.