Three of them were almost instantly asleep. Not so Ambrose. As soon as he saw the half-breed left in sole charge his smoldering suspicions leaped into activity.

"If he's meditating anything queer this is the time he'll start it!" he thought. He took care to choose his position on the floor nearest the door. He left the door open.

From the outside only occasional sounds came now. The Indians were busy and silent. Within the house it was so still that Ambrose could hear Gordon Strange puffing at his pipe.

The half-breed was sitting in the doorway outside, with his chair tipped back against the wall. By and by Ambrose heard the front legs of the chair drop to the floor, and an instinct of caution bade him close his eyes and breathe deeply like a man asleep.

Sure enough Strange came into the library. He was taking no pains to be silent. Stepping over Ambrose he crossed to the mantel, where he fumbled for matches, and striking one made believe to relight his pipe.

Now Ambrose knew that Strange had matches, for when they took John Gaviller up he had seen him light the lamp at the foot of the stairs and return the box to his pocket.

This then must be a reconnoitering expedition. Ambrose had no doubt that when the match flared up the half-breed took a survey of the sleeping men.

He left the room, and Ambrose heard the chair tipped back against the wall once more.

A little later Ambrose became conscious that Strange was at the library door again, though this time he had not heard him come.

He paused a second and pa.s.sed away as silently as a ghost--but whether back to his chair or farther into the house Ambrose could not tell.

Rising swiftly to his hands and knees he stuck his head out of the door. There was light enough from the outside to reveal the outlines of the chair--empty.

Without a thought Ambrose turned in the other direction and crept swiftly and softly through the pa.s.sage into the stair hall. He did not know what he expected to find. His heart beat thick and fast.

He scarcely suspected danger to Colina, who was strong and brave. Was it her father? Reaching the foot of the stairs he heard a velvet footfall above.

He hastened up on all fours. The stairs were thickly carpeted.

Gaining the top his strained ears detected the whisper of a sound that suggested the closing of Gaviller's door.

He knew the room. It was over the drawing-room, and cut off from the other rooms of the house. To reach the door one had to pa.s.s around the rail of the upper landing.

Arriving at the door he did indeed find it closed. Under the circ.u.mstances he was sure Colina would have left it open.

He did not stop to think of what he was doing. With infinite slow patience he turned the k.n.o.b with one hand, holding his electric torch ready in the other.

When the door parted he flashed the light on the spot where he knew the bed stood. The picture vividly revealed in the little circle of light realized his unacknowledged fears.

He saw Strange kneeling on the bed, his face hideously distorted, his two hands at the old man's throat.

Strange yelped once in mingled terror and rage like an animal surprised--and with the quickness of an animal sprang at Ambrose.

The two men went down with a crash athwart the sill, and the door slammed back against the wall. There was a desperate struggle on the floor.

Strange was nerved with the strength of a madman. He could not have seen who it was that surprised him, but in that frantic embrace he learned.

"It's you, is it?" he snarled. "I've got you now!"

Forthwith he began to shout l.u.s.tily for help. "Macfarlane! Giddings!"

Colina was already out of her room. She did not scream. The three men were on the stairs.

"Bring a light!" gasped both the struggling men.

It was Colina who lit a lamp and carried it out into the hall with a steady hand. Ambrose was seen to be uppermost. Recognizing the two men her face darkened with anger.

"What does this mean?" she cried. "Get up instantly!"

Ambrose wrenched himself free and stood up.

"Don't let him escape!" cried Strange.

Ambrose laughed a single note.

"He tried to kill your father!" panted Strange. "I arrived in the nick of time!"

Ambrose gasped and fell back in astonishment. Such stupendous effrontery was beyond the scope of his imagination.

"It's a lie!" he cried. "It was I who discovered him in the act of strangling your father!"

Then for the first Colina swayed. "Oh, G.o.d!" she murmured, "have we all gone mad!"

Macfarlane seized the lamp from her failing hand. Colina ran unevenly into her father's room. They heard her cry out within. Giddings ran to her aid. He made a light in the room and closed the door. The little parson moaned and wrung his hands.

Macfarlane had drawn his revolver. "If you make a move I'll shoot you down!" he said to Ambrose--thus making it clear whose story he believed.

"You can put it up," said Ambrose coolly. "I'm going to see this thing through."

Strange had got his grip again. His smoothness was largely restored.

He actually laughed. "He's a cool hand!" he said.

"You d.a.m.ned black villain!" said Ambrose softly. "I know you now. And you know that I know you!"

It did not improve Ambrose's case to say it, but he felt better. The half-breed changed color and edged behind Macfarlane's gun.

Colina presently reappeared, showing a white and stony face. "Mr.

Pringle," she said, "go down and lock the side door and bring me the key. The rest of you go to the library and wait for me."

Ambrose flushed darkly. That Colina should even for a moment hold the balance between him and the half-breed made him burn with anger.

Pa.s.sionate reproaches leaped to his lips, but pride forced them back.

Turning stiffly he marched downstairs before Macfarlane without a word.

She should suffer for this when he was exonerated, he vowed. That he might not be exonerated immediately did not occur to him.

In the library Strange and Macfarlane whispered together. When Pringle rejoined them all were silent. For upward of ten minutes they waited, facing each other grimly.

The strain was too great for the nerves of the little parson. He finally broke into a kind of terrified, dry sobbing.

"For G.o.d's sake say something!" he faltered. "This is too horrible!"