“No.”

Isabel dropped upon her knees before him.

“This inventor—­this man whom you insist on seeing is half insane with disappointment and anger,” she rushed on desperately.  “Remember that a vast fortune, honor, fame were at his finger tips when you—­you placed them beyond his reach by the destruction of the compact.  He has sworn to kill you.”

“I can’t go!”

“If you know that when you meet one of you will die?”

“No.”  The answer came fiercely, through clenched teeth.  Mr. Grimm disengaged his right hand and drew his revolver; the barrel clicked under his fingers as it spun.

“If I tell you that of the two human beings in this world whom I love this man is one?”

“No.”

A shuffling step sounded in the hallway just outside.  Mr. Grimm stepped back from the kneeling figure, and turned to face the door with his revolver ready.

“Great God!” It was a scream of agony.  “He is my brother!  Don’t you see?”

She came to her feet and went staggering across to the door.  The key clicked in the lock.

“Your brother!” exclaimed Mr. Grimm.

“He wouldn’t listen to me—­you wouldn’t listen to me, and now—­and now!  God have mercy!”

There was a sharp rattling, a clamor at the door, and Isabel turned to Mr. Grimm mutely, with arms outstretched.  The revolver barrel clicked under his hand, then, after a moment, he replaced the weapon in his pocket.

“Please open the door,” he requested quietly.

“He’ll kill you!” she screamed.

Exhausted, helpless, she leaned against a chair with her face in her hands.  Mr. Grimm went to her suddenly, tore the hands from her face, and met the tear-stained eyes.

“I love you,” he said.  “I want you to know that!”

“And I love you—­that’s why it matters so.”

Leaving her there, Mr. Grimm strode straight to the door and threw it open.  He saw only the outline of a thin little man of indeterminate age, then came a blinding flash under his eyes, and he leaped forward.  There was a short, sharp struggle, and both went down.  The revolver!  He must get that!  He reached for it with the one idea of disarming this madman.  The muzzle was thrust toward him, he threw up his arm to protect his head, and then came a second flash.  Instantly he felt the figure in his arms grow limp; and after a moment he rose.  The face of the man on the floor was pearly gray; and a thin, scarlet thread flowed from his temple.

[Illustration:  In a stride Mr. Grimm was beside her.]

He turned toward Isabel.  She lay near the chair, a little crumpled heap.  In a stride he was beside her, and had lifted her head to his knee.  The blue-gray eyes opened into his once, then they closed.  She had fainted.  The first bullet had pierced her arm; it was only a flesh wound.  He lifted her gently and placed her on a couch, after which he disappeared into another room.  In a little while there came the cheerful ting-a-ling of a telephone bell.