"It's impossible, Petrie. You are thinking of secret pa.s.sages, and so forth. There are none. Eltham has measured up every foot of the place. There isn't a rathole left unaccounted for; and as for a tunnel under the moat, the house stands on a solid ma.s.s of Roman masonry, a former camp of Hadrian's time. I have seen a very old plan of the Round Moat Priory as it was called. There is no entrance and no exit save by the steps. So how was the dog killed?"

I knocked out my pipe on a bar of the grate.

"We are in the thick of it here," I said.

"We are always in the thick of it," replied Smith. "Our danger is no greater in Norfolk than in London. But what do they want to do? That man in the train with the case of instruments--WHAT instruments? Then the apparition of the green eyes to-night. Can they have been the eyes of Fu-Manchu? Is some peculiarly unique outrage contemplated--something calling for the presence of the master?"

"He may have to prevent Eltham's leaving England without killing him."

"Quite so. He probably has instructions to be merciful. But G.o.d help the victim of Chinese mercy!"

I went to my own room then. But I did not even undress, refilling my pipe and seating myself at the open window. Having looked upon the awful Chinese doctor, the memory of his face, with its filmed green eyes, could never leave me. The idea that he might be near at that moment was a poor narcotic.

The howling and baying of the mastiff was almost continuous.

When all else in Redmoat was still the dog's mournful note yet rose on the night with something menacing in it. I sat looking out across the sloping turf to where the shrubbery showed as a black island in a green sea. The moon swam in a cloudless sky, and the air was warm and fragrant with country scents.

It was in the shrubbery that Denby's collie had met his mysterious death--that the thing seen by Miss Eltham had disappeared. What uncanny secret did it hold?

Caesar became silent.

As the stopping of a clock will sometimes awaken a sleeper, the abrupt cessation of that distant howling, to which I had grown accustomed, now recalled me from a world of gloomy imaginings.

I glanced at my watch in the moonlight. It was twelve minutes past midnight.

As I replaced it the dog suddenly burst out afresh, but now in a tone of sheer anger. He was alternately howling and snarling in a way that sounded new to me. The crashes, as he leapt to the end of his chain, shook the building in which he was confined. It was as I stood up to lean from the window and commanded a view of the corner of the house that he broke loose.

With a hoa.r.s.e bay he took that decisive leap, and I heard his heavy body fall against the wooden wall. There followed a strange, guttural cry ... and the growling of the dog died away at the rear of the house.

He was out! But that guttural note had not come from the throat of a dog. Of what was he in pursuit?

At which point his mysterious quarry entered the shrubbery I do not know. I only know that I saw absolutely nothing, until Caesar's lithe shape was streaked across the lawn, and the great creature went crashing into the undergrowth.

Then a faint sound above and to my right told me that I was not the only spectator of the scene. I leaned farther from the window.

"Is that you, Miss Eltham?" I asked.

"Oh, Dr. Petrie!" she said. "I am so glad you are awake. Can we do nothing to help? Caesar will be killed."

"Did you see what he went after?"

"No," she called back, and drew her breath sharply.

For a strange figure went racing across the gra.s.s. It was that of a man in a blue dressing-gown, who held a lantern high before him, and a revolver in his right hand. Coincident with my recognition of Mr.

Eltham he leaped, plunging into the shrubbery in the wake of the dog.

But the night held yet another surprise; for Nayland Smith's voice came:

"Come back! Come back, Eltham!"

I ran out into the pa.s.sage and downstairs. The front door was open. A terrible conflict waged in the shrubbery, between the mastiff and something else. Pa.s.sing round to the lawn, I met Smith fully dressed.

He just had dropped from a first-floor window.

"The man is mad!" he snapped. "Heaven knows what lurks there! He should not have gone alone!"

Together we ran towards the dancing light of Eltham's lantern. The sounds of conflict ceased suddenly. Stumbling over stumps and lashed by low-sweeping branches, we struggled forward to where the clergyman knelt amongst the bushes. He glanced up with tears in his eyes, as was revealed by the dim light.

"Look!" he cried.

The body of the dog lay at his feet.

It was pitiable to think that the fearless brute should have met his death in such a fashion, and when I bent and examined him I was glad to find traces of life.

"Drag him out. He is not dead," I said.

"And hurry," rapped Smith, peering about him right and left.

So we three hurried from that haunted place, dragging the dog with us.

We were not molested. No sound disturbed the now perfect stillness.

By the lawn edge we came upon Denby, half dressed; and almost immediately Edwards the gardener also appeared. The white faces of the house servants showed at one window, and Miss Eltham called to me from her room:

"Is he dead?"

"No," I replied; "only stunned."

We carried the dog round to the yard, and I examined his head. It had been struck by some heavy blunt instrument, but the skull was not broken. It is hard to kill a mastiff.

"Will you attend to him, Doctor?" asked Eltham. "We must see that the villain does not escape."

His face was grim and set. This was a different man from the diffident clergyman we knew: this was "Parson Dan" again.

I accepted the care of the canine patient, and Eltham with the others went off for more lights to search the shrubbery. As I was washing a bad wound between the mastiff's ears, Miss Eltham joined me. It was the sound of her voice, I think, rather than my more scientific ministration, which recalled Caesar to life. For, as she entered, his tail wagged feebly, and a moment later he struggled to his feet--one of which was injured.

Having provided for his immediate needs, I left him in charge of his young mistress and joined the search party. They had entered the shrubbery from four points and drawn blank.

"There is absolutely nothing there, and no one can possibly have left the grounds," said Eltham amazedly.

We stood on the lawn looking at one another, Nayland Smith, angry but thoughtful, tugging at the lobe of his left ear, as was his habit in moments of perplexity.

CHAPTER IX

WITH the first coming of light, Eltham, Smith and I tested the electrical contrivances from every point. They were in perfect order.

It became more and more incomprehensible how anyone could have entered and quitted Redmoat during the night. The barbed-wire fencing was intact, and bore no signs of having been tampered with.

Smith and I undertook an exhaustive examination of the shrubbery.