WHEN Piccadilly Circus, a blaze of light, was thronged with the crowds that the theatres were discharging, a motor-car came gingerly through the traffic, passed down Regent Street, and swinging along Pall Mall, headed southward across Westminster Bridge.

The rain had ceased, but underfoot the roads were sodden, and the car bespattered its occupants with black mud.

The chauffeur at the wheel turned as the car ran smoothly along the tramway lines in the Old Kent Road and asked a question, and one of the two men in the back of the car consulted the other.

"We will go to Cramer's first," said the man. Old Kent Road was a fleeting vision of closed shops, of little knots of men emerging from public-houses at the potman's strident command; Lewisham High Road, as befits that very respectable thoroughfare, was decorously sleeping; Lea, where the hedges begin, was silent; and Chislehurst was a place of the dead.

Near the common the car pulled up at a big house standing in black quietude, and the two occupants of the car descended and passed through the stiff gate, along the gravelled path, and came to a stop at the broad porch.

"I don't know what old Mauder will say," said Angel as he fumbled for the bell; "he's a methodical old chap."

In the silence they could hear the thrill of the electric bell. They waited a few minutes, and rang again. Then they heard a window opened and a sleepy voice demand —

"Who is there?"

Angel stepped back from the porch and looked up.

"Hullo, Mauder! I want you. I'm Angel."

"The devil!" said a surprised voice. "Wait a bit. I'll be down in a jiffy."

The pleasant-faced man who in dressing-gown and pajamas opened the door to them and conducted them to a cosy library was Mr. Ernest Mauder himself. It is unnecessary to introduce that world-famous publisher to the reader, the more particularly in view of the storm of controversy that burst about his robust figure in regard to the recent publication of Count Lehoff''s embarrassing "Memoirs." He made a sign to the two men to be seated, nodding to Jimmy as to an old friend.

"I am awfully sorry to disturb you at this rotten hour," Angel commenced, and the other arrested his apology with a gesture.

"You detective people are so fond of springing surprises on us unintelligent outsiders," he said, with a twinkle in his eye, "that I am almost tempted to startle you."

"It takes a lot to startle me," said Angel complacently.

"You've brought it on your own head," warned the publisher, wagging a forefinger at the smiling Angel. "Now let me tell you why you have motored down from London on this miserable night on a fairly fruitless errand."

"Eh?" The smile left Angel's face.

"Ah, I thought that would startle you! You've come about a book?"

"Yes," said Jimmy wonderingly.

"A book published by our people nine years ago?"

"Yes," the wonderment deepening on the faces of the two men.

"The title," said the publisher impressively, "is A Short Study on the Origin of the Alphabet, and the author is a half-mad old don, who was subsequently turned out of Oxford for drunkenness."

"Mauder," said Jimmy, gazing at his host in bewilderment, "you've hit it — but — "

"Ah," said the publisher, triumphant, "I thought that was it. Well, your search is fruitless. We only printed five hundred copies; the book was a failure — the same ground was more effectively covered by better books. I found a dusty old copy a few years ago, and gave it to my secretary. So far as I know, that is the only copy in existence."

"But your secretary?" said Angel eagerly. "What is his name? Where does he live?"

"It's not a 'he,'" said Mauder, "but a 'she.'"

"Her name?"

"If you had asked that question earlier in the evening I could not have told you," said Mauder, obviously enjoying the mystery he had created, "but since then my memory has been refreshed. The girl — and a most charming lady too — was my secretary for two years. I do not know what induced her to work, but I rather think she supported an invalid father."

"What is her name?" asked Angel impatiently.

"Kathleen Kent," replied the publisher, "and her address is — "

"Kathleen Kent!" repeated Jimmy in wide-eyed astonishment. "Angels and Ministers of Grace defend us!"

"Kathleen Kent!" repeated Angel with a gasp. "Well, that takes the everlasting biscuit! But," he added quickly, "how did you come to know of our errand?"

"Well," drawled the elder man, wrapping his dressing-gown round him more snugly, "it was a guess to an extent. You see, Angel, when a man has been already awakened out of a sound sleep to answer mysterious inquiries about an out-of-date book — "

"What," cried Jimmy, jumping up, "somebody has already been here?"

"It is only natural," the publisher went on, "to connect his errand with that of the second midnight intruder."

"Who has been here? For Heaven's sake, don't be funny; this is a serious business."

"Nobody has been here," said Mauder, "but an hour ago a man called me up on the telephone — "

Jimmy looked at Angel, and Angel looked at Jimmy.

"Jimmy," said Angel penitently, "write me down as a fool. Telephone! Heavens, I didn't know you were connected."

"Nor was I till last week," said the publisher, "nor will I be after tomorrow. Sleep is too precious a gift to be dissipated — "

"Who was the man?" demanded Angel.

"I couldn't quite catch his name. He was very apologetic. I gathered that he was a newspaper man, and wanted particulars in connection with the death of the author."

Angel smiled.

"The author's alive all right," he said grimly. "How did the voice sound — a little pompous, with a clearing of the throat before each sentence?"

The other nodded.

"Spedding!" said Angel, rising. "We haven't any time to lose, Jimmy."

Mauder accompanied them into the hall.

"One question," said Jimmy, as he fastened the collar of his motor-coat. "Can you give us if any idea of the contents of the book?"

"I can't," was the reply. "I have a dim recollection that much of it was purely conventional, that there were some rough drawings, and the earlier forms of the alphabet were illustrated — the sort of thing you find in encyclopaedias or in the back pages of teachers' Bibles."

The two men took their seats in the car as it swung round and turned its bright head-lamps toward London.

His mind was full of dark forebodings, and although the car bounded through the night at full speed, and the rain which had commenced to fall again cut his face, and the momentum of the powerful machine took his breath away, it went all too slowly for his mood.

One incident relieved the monotony of the journey. As the car flew round a corner in an exceptionally narrow lane it almost crashed into another car, which, driven at breakneck speed, was coming in the opposite direction. A fleeting exchange of curses between the chauffeurs, and the cars passed.

By common consent, they had headed for Kathleen's home. Streatham was deserted. As they turned the corner of the quiet road in which the girl lived, Angel stopped the car and alighted. He lifted one of the huge lamps from the socket and examined the road.

"There has been a car here less than half an hour ago," he said, pointing to the unmistakable track of wheels. They led to the door of the house.

He rang the bell, and it was almost immediately answered by an elderly lady, who, wrapped in a loose dressing-gown, bade him enter.

"Nobody seems to be surprised to see us tonight," thought Angel with bitter humour.

"I am Detective Angel from Scotland Yard," he announced himself, and the elderly lady seemed unimpressed.

"Kathleen has gone," she informed him cheerfully.

Jimmy heard her with a sinking at his heart.

"Yes," said the old lady, "Mr. Spedding, the eminent solicitor, called for her an hour ago, and" — she grew confidential — "as I know you gentlemen are very much interested in the case, I may say that there is every hope that before tomorrow my niece will be in possession of her fortune."

Jimmy groaned.

"Please, go on," said Angel.

"It came about over a book which Kathleen had given her some years ago, and which most assuredly would have been lost but for my carefulness."

Jimmy cursed her "carefulness" under his breath.

"When we moved here after the death of Kathleen's poor father I had a great number of things stored. There were amongst these an immense quantity of books, which Kathleen would have sold, but which I thought — "

"Where are these stored?" asked Angel quickly.

"At an old property of ours — the only property that my poor brother had remaining," she replied sadly, "and that because it was in too dilapidated a condition to attract buyers."

"Where, where?" Angel realized the rudeness of his impatience. "Forgive me, madam," he said, "but it is absolutely necessary that I should follow your niece at once."

"It is on the Tonbridge Road," she answered stiffly. "So far as I can remember, it is somewhere between Crawley and Tonbridge, but I am not sure. Kathleen knows the place well; that is why she has gone."

"Somewhere on the Tonbridge Road!" repeated Angel helplessly.

"We could follow the car's tracks," said Jimmy.

Angel shook his head.

"If this rain is general, they will be obliterated," he replied.

They stood a minute, Jimmy biting the sodden finger of his glove, and Angel staring into vacancy. Then Jimmy demanded unexpectedly —

"Have you a Bible?"

The old lady allowed the astonishment she felt at the question to be apparent.

"I have several."

"A teacher's Bible, with notes?" he asked.

She thought.

"Yes, there is such an one in the house. Will you wait?"

She left the room.

"We should have told the girl about Spedding — we should have told her," said Angel in despair.

"It's no use crying over spilt milk," said Jimmy quietly. "The thing to do now is to frustrate Spedding and rescue the girl."

"Will he dare — ?"

"He'll dare. Oh, yes, he'll dare," said Jimmy. "He's worse than you think, Angel."

"But he is already a ruined man."

"The more reason why he should go a step further. He's been on the verge of ruin for months, I've found that out. I made inquiries the other day, and discovered he's in a hole that the dome of St. Paul's wouldn't fill. He's a trustee or something of the sort for an association that has been pressing him for money. Spedding will dare anything " — he paused then — "but if he dares to harm that girl he's a dead man."

The old lady came in at that moment with the book, and Jimmy hastily turned over the pages. Near the end he came upon something that brought a gleam to his eye.

He thrust his hand into his pocket and drew out a notebook. He did not wait to pull up a chair, but sank on his knees by the side of the table and wrote rapidly, comparing the text with the drawings in the book.

Angel, leaning over, followed the work breathlessly.

"There — and there — and there!" cried Angel exultantly. "What fools we were, Jimmy, what fools we were."

Jimmy turned to the lady.

"May I borrow this book?" he asked. "It will be returned. Thank you. Now, Angel," he looked at his watch and made a move for the door, "we have two hours. We will take the Tonbridge Road by daybreak."

Only one other person did they disturb on that eventful night, and that was a peppery old Colonel of Marines, who lived at Blackheath.

There, before the hastily-attired old officer, as the dawn broke, Angel explained his mission, and writing with feverish haste, subscribed to the written statement by oath. Whereupon the Justice of the Peace issued a warrant for the arrest of Joseph James Spedding, Solicitor, on a charge of felony.