It was the very moment that Henson had been waiting for. All his listlessness had vanished. He sprang to his feet and made his way hurriedly across the lawn. Dark as it was, he slipped along with the ease of one who is familiar with every inch of the ground. A man half his weight and half his age could have been no more active.

He advanced to what seemed to be the very edge of the cliff and disappeared. There were rocks and grassy knolls which served as landmarks to him. A slip of the foot might have resulted in a serious accident. Above the gloom a head appeared.

"That you, Merritt?" Henson asked, hoarsely.

"Oh, it's me right enough," came the muttered reply. "Good job as I'm used to a seafaring life, or I should never have got up those cliffs. Where's the girl?"

"Oh, the girl's right enough. She's standing exactly where she can hear the cry of the suffering in distress. You can leave that part of the drama to me. She's a smart girl with plenty of pluck, but all the same I am going to make use of her. Have you got the things?"

"Got everything, pardner. Got a proper wipe over the skull, too."

"How on earth did you manage to do that?"

"Meddling with Bell, of course. Why didn't you let him come and produce his picture in peace? We should have been all ready to flabbergaster him when he did come."

"My good Merritt, I have not the slightest doubt about it. My plans are too carefully laid for them to go astray. But, at the same time, I firmly believe in having more than one plan of attack and more than two ways of escape. If we could have despoiled Bell of his picture it would have been utterly useless for him to have come here. He would have gone back preferring to accept defeat to arriving with a cock-and-bull story to the effect that he had been robbed of his treasure on the way. And so he got the best of you, eh?"

"Rather! I fancied that I was pretty strong, but—well, it doesn't matter. Here I am with the tools, and I ain't going to fail this time. Before Bell comes the little trap will be ready and you will be able to prove an alibi."

Henson chuckled hoarsely. He loved dramatic effect, and here was one to hand. He almost fancied that he could see the white outline of Chris's figure from where he stood.

"Get along," he said. "There is no time to lose."

Merritt nodded and began to make his way upward. Some way above him Chris was looking down. Her quick ear had detected some suspicious sound. She watched eagerly. Just below her the big electric light on the castle tower cast a band of flame athwart the cliff. Chris looked down steadily at this. Presently she saw a hand uplifted into the belt of flame, a hand grasping for a ledge of rock, and a quickly stifled cry rose to her lips. The thumb on the hand was smashed flat, there was a tiny pink nail in the centre.

Chris's heart gave one quick leap, then her senses came back to her. She needed nobody to tell her that the owner of the hand was James Merritt. Nor did she require any fine discrimination to perceive that he was up to no good. That it had something to do with the plot against Bell she felt certain. But the man was coming now, he could only reach the top of the cliffs just under the wall where she was standing. Chris peered eagerly down into the path of light until the intruder looked up. Then she jerked back, forgetting that she was in the darkness and absolutely invisible. The action was disastrous, however, for it shook Chris's diamond star from her head, and it fell gently almost at the feet of the climber. An instant later and his eyes had fallen upon it.

"What bloomin' luck," he said, hoarsely. "I suppose that girl yonder must have dropped it over. Well, it is as good as a couple of hundred pound to me, anyway. Little missie, you'd better take a tearful farewell of your lumps of sugar, as you'll never see them again."

To Chris's quivering indignation he slipped the star into his breast-pocket. Just for the moment the girl was on the point of crying out. She was glad she had refrained a second after, for a really brilliant thought occurred to her. She had never evolved anything more clever in her life, but she did not quite realise that as yet.

Nearer and nearer the man with the maimed thumb came. Chris stepped back into the shadow. She waited till the intruder had slipped past her in the direction of the castle, and prepared to follow at a discreet distance. Whatever he was after, she felt sure he was being ordered and abetted by Reginald Henson. Two minutes, five minutes, elapsed before she moved.

What was that? Surely a voice somewhere near her moaning for help. Chris stood perfectly still, listening for the next cry. Her sense of humanity had been touched, she had forgotten Merritt entirely. Again the stifled cry for help came.

"Who are you?" Chris shouted. "And where are you?"

"Henson," came the totally unexpected reply. "I'm down below on a ledge of rock. No, I'm not particularly badly hurt, but I dare not move."

Chris paused for a moment, utterly bewildered. Henson must have been on the look-out for his accomplice, she thought, and had missed his footing and fallen. Pity he had not fallen a little farther, she murmured bitterly, and broken his neck. But this was only for a moment, and her sense of justice and humanity speedily returned.

"I cannot see anything of you," she said.

"All the same, I can see your outline," Henson said, dismally. "I don't feel quite so frightened now. I can hang on a bit longer, especially now I know assistance is at hand. At first I began to be afraid that I was a prisoner for the night. No; don't go. If I had a rope I should have the proper confidence to swarm up again. And there is a coil of rope in the arbour close by you. Hang it straight down over that middle boulder and fasten your end round one of those iron pilasters."

The rope was there as Henson stated; indeed, he had placed it there himself. With the utmost coolness and courage Chris did as she was desired. But it took some little time to coax the rope to go over in the proper direction. There was a little mutter of triumph from below, and presently Henson, with every appearance of utter exhaustion, climbed over the ledge to the terrace. At the same moment an owl hooted twice from the long belt of trees at the bottom of the garden.

"I hope you are none the worse for your adventure?" Chris asked, politely.

Henson said sententiously that he fancied not. His familiarity with the cliffs had led him too far. If he had not fallen on a ledge of rock goodness only knows what might have happened. Would Chris be so good as to lend him the benefit of her arm back to the castle? Chris was graciously willing, but she was full of curiosity at the same time. Had Henson really been in danger, or was the whole thing some part of an elaborate and cunning plot? Henson knew perfectly well that she had taken a great fancy to the upper terrace, and he might—

Really it was difficult to know what to think. They passed slowly along till the lights here and there from the castle shone on their faces. At the same time a carriage had driven up to the hall door and a visitor was getting out. With a strange sense of eagerness and pleasure Chris recognised the handsome features and misshapen shape of Hatherly Bell.

"The expected guest has arrived," Henson said.

There was such a queer mixture of snarling anger and exulting triumph in his voice that Chris looked up. Just for an instant Henson had dropped the mask. A ray of light from the open door streamed fully across his face. The malignant pleasure of it startled Chris. Like a flash she began to see how she had been used by those miscreants.

"He is very handsome," she contrived to say, steadily.

"Handsome is that handsome does," Henson quoted. "Let us hope that Dr.
Bell will succeed in his mission. He has my best wishes."

Chris turned away and walked slowly as possible up the stairs. Another minute with that slimy hypocrite and she felt she must betray herself. Once out of sight she flew along the corridor and snapped up the electric light. She fell back with a stifled cry of dismay, but she was more sorrowful than surprised.

"I expected it," she said. "I knew that this was the thing they were after."

The precious copy of Rembrandt was no longer there!