He heard a rustle behind him, and there she was. She had on a gray fur coat and a lively little hat. Her cheeks were delicately tinted by the winter air. Aubrey rose.

"Why, Mr. Gilbert!" she said. "Where have you been keeping yourself when I wanted to see you so badly? I haven't seen you, not to talk to, since last Sunday."

He found it impossible to say anything intelligible. She threw off her coat, and went on, with a wistful gravity that became her even more than smiles:

"Mr. Mifflin has told me some more about what you did last week--I mean, how you took a room across the street and spied upon that hateful man and saw through the whole thing when we were too blind to know what was going on. And I want to apologize for the silly things I said that Sunday morning. Will you forgive me?"

Aubrey had never felt his self-salesmanship ability at such a low ebb.

To his unspeakable horror, he felt his eyes betray him. They grew moist.

"Please don't talk like that," he said. "I had no right to do what I did, anyway. And I was wrong in what I said about Mr. Mifflin. I don't wonder you were angry."

"Now surely you're not going to deprive me of the pleasure of thanking you," she said. "You know as well as I do that you saved my life--all our lives, that night. I guess you'd have saved poor Bock's, too, if you could." Her eyes filled with tears.

"If anybody deserves credit, it's you," he said. "Why, if it hadn't been for you they'd have been away with that suitcase and probably Metzger would have got his bomb on board the ship and blown up the President----"

"I'm not arguing with you," she said. "I'm just thanking you."

It was a happy little party that sat down in Roger's dining room that evening. Helen had prepared Eggs Samuel Butler in Aubrey's honour, and Mr. Chapman had brought two bottles of champagne to pledge the future success of the bookshop. Aubrey was called upon to announce the result of his conferences with the secret service men who had been looking up Weintraub's record.

"It all seems so simple now," he said, "that I wonder we didn't see through it at once. You see, we all made the mistake of a.s.suming that German plotting would stop automatically when the armistice was signed.

It seems that this man Weintraub was one of the most dangerous spies Germany had in this country. Thirty or forty fires and explosions on our ships at sea are said to have been due to his work. As he had lived here so long and taken out citizen's papers, no one suspected him. But after his death, his wife, whom he had treated very brutally, gave way and told a great deal about his activities. According to her, as soon as it was announced that the President would go to the Peace Conference, Weintraub made up his mind to get a bomb into the President's cabin on board the George Washington. Mrs. Weintraub tried to dissuade him from it, as she was in secret opposed to these murderous plots of his, but he threatened to kill her if she thwarted him. She lived in terror of her life. I can believe it, for I remember her face when her husband looked at her.

"Of course to make the bomb was simple enough for Weintraub. He had an infernally complete laboratory in the cellar of his house, where he had made hundreds. The problem was, how to make a bomb that would not look suspicious, and how to get it into the President's private cabin. He hit on the idea of binding it into the cover of a book. How he came to choose that particular volume, I don't know."

"I think probably I gave him the idea quite innocently," said Roger.

"He used to come in here a good deal and one day he asked me whether Mr. Wilson was a great reader. I said that I believed he was, and then mentioned the Cromwell, which I had heard was one of Wilson's favourite books. Weintraub was much interested and said he must read the book some day. I remember now that he stood in that alcove for some time, looking over it."

"Well," said Aubrey, "it must have seemed to him that luck was playing into his hands. This man Metzger, who had been an a.s.sistant chef at the Octagon for years, was slated to go on board the George Washington with the party of cooks from that hotel who were to prepare the President's meals. Weintraub was informed of all this from someone higher up in the German spy organization. Metzger, who was known as Messier at the hotel, was a very clever chef, and had fake pa.s.sports as a Swiss citizen. He was another tool of the organization. By the original scheme there would have been no direct communication between Weintraub and Metzger, but the go-between was spotted by the Department of Justice on another count, and is now behind bars at Atlanta.

"It seems that Weintraub had conceived the idea that the least suspicious way of pa.s.sing his messages to Metzger would be to slip them into a copy of some book--a book little likely to be purchased--in a second-hand bookshop. Metzger had been informed what the book was, but--perhaps owing to the unexpected removal of the go-between--did not know in which shop he was to find it. That explains why so many booksellers had inquiries from him recently for a copy of the Cromwell volume.

"Weintraub, of course, was not at all anxious to have any direct dealings with Metzger, as the druggist had a high regard for his own skin. When the chef was finally informed where the bookshop was in which he was to see the book, he hurried over here. Weintraub had picked out this shop not only because it was as unlikely as any place on earth to be suspected as a channel of spy codes, but also because he had your confidence and could drop in frequently without arousing surprise. The first time Metzger came here happened to be the night I dined with you, as you remember."

Roger nodded. "He asked for the book, and to my surprise, it wasn't there."

"No: for the excellent reason that Weintraub had taken it some days before, to measure it so he could build his infernal machine to fit, and also to have it rebound. He needed the original binding as a case for his bomb. The following night, as you told me, it came back. He brought it himself, having provided himself with a key to your front door."

"It was gone again on Thursday night, when the Corn Cob Club met here,"

said Mr. Chapman.

"Yes, that time Metzger had taken it," said Aubrey. "He misunderstood his instructions, and thought he was to steal the book. You see, owing to the absence of their third man, they were working at cross purposes.

Metzger, I think, was only intended to get his information out of the book, and leave it where it was. At any rate, he was puzzled, and inserted that ad in the Times the next morning--that LOST ad, you remember. By that, I imagine, he intended to convey the idea that he had located the bookshop, but didn't know what to do next. And the date he mentioned in the ad, midnight on Tuesday, December third, was to inform Weintraub (of whose ident.i.ty he was still ignorant) when Metzger was to go on board the ship. Weintraub had been instructed by their spy organization to watch the LOST and FOUND ads."

"Think of it!" cried t.i.tania.

"Well," continued Aubrey, "all this may not be 100 per cent. accurate, but after putting things together this is how it dopes out. Weintraub, who was as canny as they make them, saw he'd have to get into direct touch with Metzger. He sent him word, on the Friday, to come over to see him and bring the book. Metzger, meanwhile, had had a bad fright when I spoke to him in the hotel elevator. He returned the book to the shop that night, as Mrs. Mifflin remembers. Then, when I stopped in at the drug store on my way home, he must have been with Weintraub. I found the Cromwell cover in the drug-store bookcase--why Weintraub was careless enough to leave it there I can't guess--and they spotted me right away as having some kind of hunch. So they followed me over the Bridge and tried to get rid of me. It was because I got that cover on Friday night that Weintraub broke into the shop again early Sunday morning. He had to have the cover of the book to bind his bomb in."

Aubrey was agreeably conscious of the close attention of his audience.

He caught t.i.tania's gaze, and flushed a little.

"That's pretty nearly all there is to it," he said. "I knew that if those guys were so keen to put me out of the way there must be something rather rotten on foot. I came over to Brooklyn the next afternoon, Sat.u.r.day, and took a room across the street."

"And we went to the movies," chirped t.i.tania.

"The rest of it I think you all know--except Metzger's visit to my lodgings that night." He described the incident. "You see they were trailing me pretty close. If I hadn't happened to notice the cigar at my window I guess he'd have had me on toast. Of course you know how wrongly I doped it out. I thought Mr. Mifflin was running with them, and I owe him my apology for that. He's laid me out once on that score, over in Philadelphia."

Humourously, Aubrey narrated how he had sleuthed the bookseller to Ludlow Street, and had been worsted in battle.

"I think they counted on disposing of me sooner or later," said Aubrey.

"They framed up that telephone call to get Mr. Mifflin out of town.

The point in having Metzger come to the bookshop to get the suitcase was to clear Weintraub's skirts if possible. Apparently it was just a bag of old books. The bombed book, I guess, was perfectly harmless until any one tried to open it."

"You both got back just in the nick of time," said t.i.tania admiringly.

"You see I was all alone most of the afternoon. Weintraub left the suitcase about two o'clock. Metzger came for it about six. I refused to let him have it. He was very persistent, and I had to threaten to set Bock at him. It was all I could do to hold the dear old dog in, he was so keen to go for Metzger. The chef went away, and I suppose he went up to see Weintraub about it. I hid the suitcase in my room. Mr.

Mifflin had forbidden me to touch it, but I thought that the safest thing to do. Then Mrs. Mifflin came in. We let Bock into the yard for a run, and were getting supper. I heard the bell ring, and went into the shop. There were the two Germans, pulling down the shades. I asked what they meant by it, and they grabbed me and told me to shut up. Then Metzger pointed a pistol at me while the other one tied up Mrs. Mifflin."

"The d.a.m.ned scoundrels!" cried Aubrey. "They got what was coming to them."

"Well, my friends," said Mr. Chapman, "Let's thank heaven that it ended no worse. Mr. Gilbert, I haven't told you yet how I feel about the whole affair. That'll come later. I'd like to propose the health of Mr. Aubrey Gilbert, who is certainly the hero of this film!"

They drank the toast with cheers, and Aubrey blushed becomingly.

"Oh, I forgot something!" cried t.i.tania. "When I went shopping this afternoon I stopped in at Brentano's, and was lucky enough to find just what I wanted. It's for Mr. Gilbert, as a souvenir of the Haunted Bookshop."

She ran to the sideboard and brought back a parcel.

Aubrey opened it with delighted agitation. It was a copy of Carlyle's Cromwell. He tried to stammer his thanks, but what he saw--or thought he saw--in t.i.tania's sparkling face--unmanned him.

"The same edition!" said Roger. "Now let's see what those mystic page numbers are! Gilbert, have you got your memorandum?"

Aubrey took out his notebook. "Here we are," he said. "This is what Weintraub wrote in the back of the cover."

153 (3) 1, 2.

Roger glanced at the notation.

"That ought to be easy," he said. "You see in this edition three volumes are bound in one. Let's look at page 153 in the third volume, the first and second lines."

Aubrey turned to the place. He read, and smiled.

"Right you are," he said.

"Read it!" they all cried.

"To seduce the Protector's guard, to blow up the Protector in his bedroom, and do other little fiddling things."

"I shouldn't wonder if that's where he got his idea," said Roger.

"What have I been saying right along--that books aren't merely dead things!"