"You don't understand, don't you? We don't understand either. But, I must say, we thought _you_ did!"

With that he turned to go. But Robin caught him by the arm.

"Listen to me, Horace," he said. "I'm not going to quarrel with you in this house of death. But you're going to tell here and now what you meant by that remark. Do you understand? I'm going to know!"

Horace Trevert shook himself free.

"Certainly you shall know," he answered with _hauteur_, "but I must say I should have thought that, as a lawyer and so on, you would have guessed my meaning without my having to explain. What I mean is that, now that Hartley Parrish is dead, there is only one man who knows what drove him to his death. And that's yourself! Do you want it plainer than that?"

Robin took a step back and looked at his friend. But he did not speak.

"And now," the boy continued, "perhaps you will realize that your presence here is disagreeable to Mary ..."

"Did Mary ask you to tell me this?" Robin broke in.

His voice had lost its hardness. It was almost wistful. The change of tone was so marked that it struck Horace. He hesitated an instant.

"Yes," he blurted out. "She doesn't want to see you again. I don't want to be offensive, Robin.."

"Please don't apologize," said Greve. "I quite understand that this is your sister's house now and, of course, I shall leave at once. I'll ask Jay to pack my things if you could order the car ..."

The boy moved towards the door. Before he reached it Robin called him back.

"Horace," he said pleasantly, "before you go I want you to answer me a question. Think before you speak, because it's very important. When you got into the library yesterday evening through the window, you smashed the gla.s.s, didn't you?"

Horace Trevert nodded.

"Yes," he replied, looking hard at Robin.

"Why?"

"To get into the room, of course!"

"Was the window bolted?"

The boy stopped and thought.

"No," he said slowly, "now I come to think of it, I don't believe it was. No, of course, it wasn't. I just put my arm through the broken pane and shoved the window up. But why do you ask?"

"Oh, nothing," answered Robin nonchalantly. "I just was curious to know, that's all!"

Horace stood and looked at him for an instant. Then he went out.

A quarter of an hour later, Hartley Parrish's Rolls-Royce glided through the straggling main street of Stevenish. A chapel bell tinkled unmusically, and on the pavements, gleaming with wet, went a procession of neatly dressed townsfolk bound, prayer-book in hand, for their respective places of worship. A newsboy, sorting out the Sunday newspapers which had just come down by train from London, was the only figure visible on the little station platform. Robin bought a selection.

"There's all about Mr. Parrish," said the boy, "'im as they found dead up at 'Arkings las' night. And the noospapers 'asn't 'arf been sendin'

down to-day ... reporters and photographers ... you oughter seen the crowd as come by the mornin' train ..."

"I wonder what they'll get out of Manderton," commented Robin rather grimly to himself as his train puffed leisurely, after the habit of Sunday trains, into the quiet little station.

In the solitude of his first-cla.s.s smoker he unfolded the newspapers.

None had more than the brief fact that Hartley Parrish had been found dead with a pistol in his hand, but they made up for the briefness of their reports by long accounts of the dead man's "meteoric career."

And, Robin noted with relief, hitherto Mary Trevert's name was out of the picture.

He dropped the papers on to the seat, and, as the train steamed serenely through the Sunday calm of the country towards London's outer suburbs, he reviewed in his mind such facts as he had gleaned regarding the circ.u.mstances of his late host's death.

He would, he told himself, accept for the time being as _facts_ what, he admitted to himself, so far only seemed to be such. Hartley Parrish, then, had been seated in his library at his desk with the door locked.

The fire was smoking, and therefore he had opened the window. According to Horace Trevert, the window had not been bolted when he had entered the library, for, after smashing the pane in the a.s.sumption that the bolt was shot, he had had no difficulty in pushing up the window.

Hartley Parrish had opened the window himself, for on the nail of the middle finger of his left hand Robin had seen, with the aid of the magnifying-gla.s.s, a tiny fragment of white paint.

Who had closed it? He had no answer ready to _that_ question.

Now, as to the circ.u.mstances of the shooting. The suicide theory invited one to believe that Hartley Parrish had got up from his desk, pushing back his chair, had gone round it until he stood between the desk and the window, and had there shot himself through the heart. Why should he have done this?

Robin had no answer ready to this question either. He pa.s.sed on again.

Bude had heard loud voices a very few minutes before Mary had heard the shot. That morning's experiments had shown that Bude could have heard these sounds only by way of the open window of the library and the open doors of the garden and the library corridor. Additional proof, if Bude had heard aright, that the library window was open.

Leaning back in his seat, his finger-tips pressed together, Robin Greve resolutely faced the situation to which his deductions were leading him.

"The voice heard at the open window," he told himself, "was the voice of the man who murdered Parrish and who closed the window, that is, of course, if the murder theory proves more conclusive than that of suicide."

This brought him back to his investigations in the rosery. The abrasure he had discovered on the timber upright was the mark of a bullet and a mark freshly made at that. Moreover, it had almost certainly been fired from the library window--from the window which Parrish had opened; the angle at which it had struck and marked the tree showed that almost conclusively.

Yet there had been but one shot! If only he had been able to find that bullet in the rosery! Robin thought ruefully of his long hunt among the sopping rose-bushes.

Yes, there had been only one shot. Mary Trevert had stated it definitely. Besides, the bullet that had killed Hartley Parrish had been fired from his own revolver and had been found in the body. Robin Greve felt the murder theory collapsing about him. But the suicide theory did not stand up, either. What possible, probable motive had Hartley Parrish for taking his own life?

"He wasn't the man to do it!"

The wheels of the train took up the rhythm of the phrase and dinned it into his ears.

"He wasn't the man to do it!"

The riddle seemed more baffling than ever.

Robin thrust one hand into his right-hand pocket to get his pipe, his other hand into his left-hand pocket to find his pouch. His left hand came into contact with a little ball of paper.

He drew it out. It was the little ball of slatey-blue paper he had found on the floor of the library beside Hartley Parrish's dead body.

CHAPTER XII

MR. MANDERTON IS NONPLUSSED

Horace Trevert walked abruptly into Mary's Chinese boudoir. Lady Margaret and the girl were standing by the fire.