Michael Brixan braced himself for the supreme and futile struggle. And then, to his amazement, the ape stopped, and his bird noise became a harsh chatter. Raising himself erect, he beat quickly on his great hairy chest, and the sound of the hollow drumming was awful.

Yet through that sound and above it, Michael heard a curious hiss⁠—it was the faint note of escaping steam, and he looked round. On the top of the wall squatted a man, and Michael knew him at once. It was the brown-faced stranger he had seen that day in Chichester.

The drumming and the hissing grew louder and then Michael saw a bright, curved thing in the brown man’s hand. It was a sword, the replica of that which hung above Sir Gregory’s fireplace.

He was still wondering when the brown man dropped lightly to the ground, and Bhag, with a squeal that was almost human, turned and fled. Michael watched the Thing, fascinated, until it disappeared into the darkness.

“My friend,” said Michael in Dutch, “you came at a good moment.”

He turned, but the brown man had vanished as though the earth had swallowed him. Shading his eyes against the starlight, he presently discerned a dark shape moving swiftly in the shadow of the wall. For a second he was inclined to follow and question the brown man, but decided upon another course. With some difficulty he surmounted the wall and dropped to the other side. Then, tidying himself as well as he could, he made the long circuit to the gate of Griff Towers, and boldly walked up to the house, whistling as he went.

There was nobody in sight as he crossed the “parade ground,” and his first step was to search for and find his pistol.

He must know that the girl was safe before he left the place. He had seen her car waiting on the road outside. His hand was raised to the bell when he heard footsteps in the hall, and listened intently: there was no doubt that one of the voices was Stella Mendoza’s, and he drew back again to cover.

The girl came out, followed by Sir Gregory, and from their tone, a stranger unacquainted with the circumstances of their meeting might have imagined that the visit had been a very ordinary one, in spite of the lateness of the hour.

“Good night, Sir Gregory,” said the girl, almost sweetly. “I will see you tomorrow.”

“Come to lunch,” said Gregory’s voice, “and bring your friend. Shall I walk with you to the car?”

“No, thank you,” she said hastily.

Michael watched her till she was out of sight, but long before then the big door of Griff Towers had closed, and the familiar rattle of chains told him that it was closed finally.

Where was Foss? He must have gone earlier, if Foss it was. Michael waited till all was quiet, and then, tiptoeing across the gravel, followed the girl. He looked about for the little brown man, but he was not in sight. And then he remembered that he had left the hook ladder hanging to the window on the stairs, and went back to retrieve it. He found the ladder as it had been left, unscrewed and packed it in the canvas bag, and five minutes later he was taking his motorcycle from its place of concealment.

A yellow light showed in the window of Mr. Longvale’s dining-room, and Michael had half a mind to call upon him. He could tell him, at any rate, something of that oval-faced girl in the upper room of the tower. Instead, he decided to go home. He was tired with the night’s work, a little disappointed. The tower had not revealed as tremendous a secret as he had hoped. The girl was a prisoner, obviously; had been kidnapped for Sir Gregory’s pleasure, and brought to England on his yacht. Such things had happened; there had been a case in the courts on curiously parallel lines only a few months before. At any rate, it did not seem worth while to put off his bedtime.

He had a hot bath, made himself some chocolate and, before retiring, sat down to sum up his day’s experience. And in the light of recent happenings he was less confident that his first solution of the Headhunter mystery was the correct one. And the more he thought, the less satisfied he was, till at last, in sheer disgust at his own vacillation of mind, he turned out the light and went to bed.

He was sleeping peacefully and late the next morning when an unexpected visitor arrived, and Michael sat up in bed and rubbed his eyes.

“I’ve either got nightmare or it’s Staines,” he said.

Major Staines smiled cheerfully.

“You’re awake and normal,” he said.

“Has anything happened?” asked Michael, springing out of bed.

“Nothing, only there was a late dance last night and an early train this morning, and I decided to atone for my frivolity by coming down and seeing how far you had got in the Elmer case.”

“Elmer case?” Michael frowned. “Good Lord! I’d almost forgotten poor Elmer!”

“Here’s something to remind you,” said Staines.

He fished from his pocket a newspaper cutting. Michael took it and read:

“Is your trouble of mind or body incurable? Do you hesitate on the brink of the abyss? Does courage fail you? Write to Benefactor, Box⁠—”

“What is this?” asked Michael, frowning.

“It was found in the pocket of an old waistcoat that Elmer was wearing a few days before he disappeared. Mrs. Elmer was going through his clothes with the idea of selling them, when she found this. It appeared in the Morning Telegram of the fourteenth⁠—that is to say, three or four days before Elmer vanished. The box number at the end, of course, is the box number of the newspaper to which replies were sent. There is a record that four letters reached the ‘Benefactor,’ who, so far as we have been able to discover, had these particular letters readdressed to a little shop in Stibbington Street, London. Here they were collected by a woman, evidently of the working class, and probably a charlady from the appearance which has been circulated. Beyond that, no further trace has been obtainable. Similar advertisements have been found by search in other newspapers, but in these cases the letters were sent to an accommodation address in South London, where apparently the same woman collected them. With every new advertisement the advertiser changes his address. She was a stranger to each neighbourhood, by the way; and from what shopkeepers have told Scotland Yard, she seemed to be a little off her head, for she was in the habit of mumbling and talking to herself. Her name is Stivins⁠—at least, that is the name she always gave. And the notes she brought were usually signed ‘Mark’⁠—that is to say, the notes authorizing the shopkeepers to hand the letters to her. That she is a native of London there is no doubt, but so far the police have not trailed her.”

“And suppose they do?” asked Michael. “Do you connect the advertisement with the murders?”

“We do and we do not,” replied the other. “I merely point out that this advertisement is a peculiar one, and in all the circumstances a little suspicious. Now what is the theory you wanted to give me?”

For an hour Michael spoke, interrupted at intervals by questions which Staines put to him.

“It is a queer idea, almost a fantastical one,” said Staines gravely, “but if you feel that you’ve got so much as one thread in your hands, go right ahead. To tell you the truth,” in a burst of confidence, “I had a horrible feeling that you had fallen down; and since I do not want our department to be a source of amusement to Scotland Yard, I thought I’d come along and give you the result of my own private investigations. I agree with you,” he said later, as they sat at breakfast, “that you want to go very, very carefully. It is a delicate business. You haven’t told the Scotland Yard men your suspicions?”

Michael shook his head.

“Then don’t,” said the other emphatically. “They’d be certain to go along and put the person you suspect under arrest, and probably that would destroy the evidence that would convict. You say you have made a search of the house?”

“Not a search: I’ve made a rough inspection.”

“Are there cellars?”

“I should imagine so,” said Michael. “That type of house usually has.”

“Outhouses where⁠—?”

Michael shook his head.

“There are none, so far as I have been able to see.”

Michael walked down to the railway station with his chief, who told him he was leaving in a much more cheerful frame of mind than he had been in when he arrived.

“There’s one warning I’ll give to you, Mike,” said Staines as the train was about to pull out of the station, “and it is to watch out for yourself! You’re dealing with a ruthless and ingenious man. For heaven’s sake do not underrate his intelligence. I don’t want to wake up one morning to learn that you have vanished from the ken of man.”