He spun toward the desk. I saw the bunching of his shoulder muscles under his jacket and my finger tensed, hovering against the trigger. The black crystal on the desk top winked with reflected light.
"And what is that supposed to be?"
"The alien, Doctor. I used a flame on it. It was the only thing I could think of that would be effective."
I thought the skin of his neck paled, but I couldn't be sure. Again I was struck by the degree of his self-control. But perhaps he has no emotions, I thought. Perhaps he doesn't feel anything at all—love or hate, excitement or fear. He might be able to analyze them coldly but he wouldn't understand them. The thought excited me. Here was a weakness in the alien mind.
"You are a sick man, Mr. Cameron," Dr. Temple said quietly. "I realized that you were ill when you talked to me on Saturday—but I did not then believe you capable of murder. If you've really killed someone you are in serious trouble. And you have also been hurt. Your hand—"
"I only need one good finger to kill you," I said. "I could have done it as you walked through the door but I wanted you to know it was coming."
He smiled thinly. "And why should you want to kill me?"
"Because you are one of them—the leader. I should have known it before, I guess. It wasn't until I saw the hardened crystal that I knew. That's how you got to earth, Doctor—as a pair of innocent-looking crystals. I don't pretend to understand what kind of creature you are but I've seen the other crystal there in both its frozen and its active states. I imagine you were the first one to be activated. The real Dr. Temple received the crystals for research. He was probably the first one to touch them with his bare hands—or his tongue."
"You have a vivid imagination, Mr. Cameron."
"Then all you had to do was find a suitable subject for the other crystal. Helen Darrow was a shrewd choice. She would never be suspected and she could work closely with you under the guise of a student."