"_Averti!_"

Carpenter gave a soft whistle of satisfaction. French, it was--his hunch had not deceived him. The key-word was found!

Swiftly he worked out the rest of the cipher, setting down the letters of the translation without regard to words. "_Averti_" was evident because it was the first word. At the end, he had this result:

AVERTIQUELALLEMAGNEAENGAG EUNOFFICIERADECELERLAFORM ULESECRETEDESETATSUNISEMP LOYEEACOLLODONNIERLAFULMI COTONPOURLAPOUDRESANSFUME EALARTILLERIEDEGROSCALIBR EETQUEMADELINESPENCEREMIS SAIREDELALLEMAGNEAPARISPH OTOGRAPHIECIINCLUSEAETECH ARGEEDELARECEVOIRNESEPEUT DECOUVRIRLENOMDUTRAITRESP ENCERESTPARTIEPOURNEWYORK SURLALUSITANIAQUIDOITARRI VERLEQUATORZEATOUTEFORCEI NTERCEPTEZLAFORMULEOUEMPE CHEZAMOINSQUELALLEMAGNENE LOBTIENNESPENCERSIMPORTAN TEALAFRANCE

There was not the least doubt as to it being in French--the last three words, as well as the first, proved it; also that he had the correct key-word. It only remained now to separate the result into words. And this puzzle presented no difficulties to Carpenter; he quickly marshalled it into form:

"_Averti que l'Allemagne a engage un officier a deceler la formule secrete des etats-Unis employee a collodonnier la fulmi-coton pour la poudre sans fumeee a l'artillerie de gros calibre; et que Madeline Spencer, emissaire de l'Allemagne a Paris,--photographie ci, incluse--a ete de chargee la recevoir. Ne se peut decouvrir le nom du traitre.

Spencer est partie pour New York sur la Lusitania qui doit arriver le quatorze. a toute force interceptez la formule; ou empechez a moins que l'Allemagne ne l'obtienne. Spencer pas importante a la France._"

And under it he wrote the English translation: "Informed Germany has induced an officer to betray United States secret formula for colloding process of treating gun-cotton for smokeless powder for high power guns, and that Madeline Spencer, a German Secret agent in Paris, photograph enclosed herein, is delegated to receive same. Cannot ascertain name of traitor. Spencer sailed Lusitania, due New York, fourteenth. Take any means to intercept formula; or at least to prevent Germany obtaining it.

Spencer not essential to France."

_Spencer not essential to France!_ Surely this woman had great power, either of knowledge or of friends; she resided in Paris, yet France was reluctant to lift hand against her so long as she was on French soil.

Well, he would turn the matter over to Harleston; let him decide whether it was to be thumbs up or thumbs down for her Alluringness. Furthermore, the meeting with Snodgra.s.s now a.s.sumed much significance. Snodgra.s.s was an ex-army officer. Harleston must be warned at once.

He tried for him at the Collingwood, the Cosmopolitan, the Rataplan, and finally at the Chateau. He got him there.

"Can you come here at once?" he asked.

"Not well," said Harleston, "I've an appointment."

"Forget it!" Carpenter exclaimed. "I've found the key-word and made the translation. It's serious--Very well, come right in; I'll be waiting."

Harleston scribbled a note to Mrs. Clephane and sent it up by a page; he would be back in half an hour; would she meet him in the Alley.

XXII

THE RATAPLAN

A moment before Harleston's return, Madeline Spencer, stepping out of the F Street elevator, was met by Snodgra.s.s who had been walking up and down the lobby. They took a taxi and sped away; followed closely by another taxi, which their driver was most careful not to distance. A second later Harleston entered the corridor. As he was about to greet Mrs. Clephane, a man approached him and said:

"They have started, sir; Burke's just behind in a taxi--and both drivers are wise. They're bound for the Rataplan."

"Follow them and wait just outside," Harleston ordered--and turned to Mrs. Clephane. "I must go to the Rataplan at once," said he. "Let us lunch there. The end of the affair of the cab of the sleeping horse is in sight; I thought you might like to see it."

"I want to see it!" Mrs. Clephane exclaimed. "Have you found the key-word?"

"Carpenter found it--I'll tell you about it on the way out. Come along, little lady."

"But why do you suspect Captain Snodgra.s.s?" she inquired, when Harleston had finished his account. "He would not have access to the formula, would he?"

"The man that has access to such secrets never is the man who actually delivers," he explained; "he has a confederate. Snodgra.s.s is the confederate, we think."

"Is this secret colloding process of gun-cotton so tremendously valuable?" she asked.

"It's a secret for which any nation would give millions of dollars. It's admittedly the most powerful explosive ever discovered, as well as the easiest handled. Temperature, weather, ordinary shock have absolutely no effect on it; in fire it simply chars and doesn't explode. Yet when it is exploded by the proper method, lyddite, dynamite, and all the other ites, are as a gentle zephyr in comparison. Now tell me about last night; where were you?"

"After you left," she explained, "I wrote some letters, and then went into the corridor to drop them in the chute beside the elevator shaft; as I approached, the car came down with Mrs. Spencer in it. Something impelled me to follow her; and running back I grabbed a cloak, and dashed for the elevator, catching it on the fly. She wasn't in the main corridor; on a chance, I hurried to the F Street entrance; I got there just as she stepped into a taxi and shot away. Instantly I called another taxi and told the driver to follow the car that had just departed. He did for a little way; but in a sudden halt of traffic at Vermont Avenue and H Street, where, you may remember, the street is torn up, we lost the other taxi; and though we drove around the north-west section for more than an hour on the chance that we'd come up with it--my driver knew the other driver--we never did come up with it. But as we rolled up to the Chateau, Mrs. Spencer was alighting from a limousine with a tall, fine-looking, fair-haired chap who had the walk of a military man."

"Snodgra.s.s," Harleston observed.

"She saw me; and, with a maliciously charming smile, nodded and went on. In the corridor I came on some friends and we talked awhile. Then I went up to my apartment, got your message, and telephoned to you."

"Don't do it again," he cautioned. "It was very dangerous."

They turned in at the Rataplan and drew up at the carriage entrance.

Harleston helped Mrs. Clephane from the taxi and they pa.s.sed into the Club-House.

He inquired of the doorman whether Mr. Carpenter was in, and another servant, who overheard the question, added that Mr. Carpenter was in the dining-room. Harleston and Mrs. Clephane went directly in and to a table next to Carpenter's. Three tables away were Madeline Spencer and Snodgra.s.s.

Harleston nodded to Mrs. Spencer and to Snodgra.s.s, then spoke to Carpenter and invited him over.

"I don't know if you will remember me, Mrs. Clephane," said Carpenter, coming across. "I met you several years ago in Paris."

"Yes, indeed, Mr. Carpenter, I remember you!" Mrs. Clephane replied.

"Anything?" Harleston asked, without moving his lips.

"Nothing. I was here when they arrived," Carpenter replied in the same manner--and went back to his table.

"Who is the woman with Harleston?" Snodgra.s.s asked Mrs. Spencer. "I've never seen her."

"A Mrs. Clephane," Madeline Spencer replied. "She's very good-looking, isn't she?"

"I'm perfectly satisfied with the lady immediately in my fore," he smiled. "I don't run to blondes--"

"When you're with a brunette!" she smiled back.

"I don't run to anyone when I'm with you," he replied with quiet earnestness, leaning toward her across the table.

She shot him a knowing glance. Last night she had held him to strict propriety. Today in the taxi she had deliberately set herself to fascinate him, and had succeeded well. She had been demurely tantalizing--holding him at a distance, letting him come a little nearer, bringing him up sharply; all the tricks of the trade executed with a perfection of technic and a mastery of effect. Snodgra.s.s, with all his experience, was but a novice in her hands; she always struck directly at the affections--got them: and then the rest was easy. She never lost her head, nor allowed her own affections to become involved; save only twice--and both those times she had failed. Snodgra.s.s, she had learned through inquiries, had quite sufficient money to make him worth her while; moreover, he was such a big, good-natured, dependable chap--and a gentleman. If he had not been a gentleman he would not have attracted Madeline Spencer for an instant. She dealt only in gentlemen.

She had not told Snodgra.s.s of the Clephane letter, nor anything as to Harleston except to refer casually to him as the confidential emissary in delicate matters of the State Department. She had found that Snodgra.s.s was not the actual man in the case; that he was simply a friendly confederate, or rather, to use his own words, "a friend of Davidson." She had expected that the package or letter would be delivered to her in the taxi; but Snodgra.s.s had told her as soon as they were started that Davidson would forward it to him at the Rataplan by mail, not later than the two o'clock delivery. He would get it as they were leaving and transfer it to her, accepting the consideration as specified by Davidson, and receipting for it. He said flatly that he did not want to know the contents of the letter; he was doing this favour for Davidson. He understood that it was to be entirely _sub rosa_ and that nothing must ever transpire as to it. Therefore he was prepared to forget the entire episode the moment it was over; the epochal meetings with her he would not forget, nor would he permit her to forget him if constant devotion and a.s.siduous attention were of avail. To which she had made a most demurely fitting answer, and the conversation thereafter grew exceedingly confidential. Oh, they were getting on very well indeed when the Rataplan was reached. And they were still progressing very well--in a discreetly informal way.

The entrance of Mrs. Clephane and Harleston was unexpected to Mrs.

Spencer; Carpenter was a stranger to her and she had thought nothing of him; but when he spoke to Harleston, and seemed to know Mrs. Clephane, she put him on the list of the enemy. She kept him there when Snodgra.s.s told her his name and position in the Diplomatic Service and that it was reputed there was no cipher too difficult for him to solve.

"We would better be very circ.u.mspect," she said low. "I think that these two men are here to watch us; they know that I'm in the Secret Service, of Germany, and they're naturally suspicious of me."