“How do I know that someone else was involved?”
He looked at the giant Lieutenant Keku. “Do you remember when we took Mellon to his quarters after he tried to brain von Liegnitz? We found half a bottle of wine. That disappeared during the night—because it was loaded with Lysodine, and the killer didn’t want it analyzed.
“But, more important, as far as Snookums is concerned, is that I looked over the books on Mellon’s desk that night. There weren’t many, and I knew which ones they were. When Captain Quill and I checked Mellon’s books after his death, someone had returned his copy of The Christian Religion and Symbolic Logic. It had not been there the night before.”
“Mike,” said Pete Jeffers, “why would anybody here want to kill Lew thataway? What would anybody have against him?”
“That’s the sad part about it, Pete. Our murderer didn’t even have anything against Mellon. He wanted—and still wants—to kill me.”
“I don’t quite follow,” Jeffers said.
“I’ll give it to you piece by piece. The killer wanted no mystery connected with my death. There are reasons for that, which I’ll come to in a moment. He had to put the blame on someone or something else.
“His first choice was Snookums. It occurred to him that he could take advantage of the fact that I’m called ‘Mike the Angel.’ He borrowed Mellon’s books and began pumping theology into Snookums. He figured that would be safe enough. Mellon would certainly lend him the books if he pretended an interest in religion; if anything came out afterward, he could—he thought—claim that Snookums got hold of the books without his knowing it. And that sort of muddy thinking is typical of our killer.
“He told Snookums that I was an angel, you see. I couldn’t be either hurt or killed. He protected himself, of course, by telling Snookums that he mustn’t reveal his source of data. If Snookums told, then the killer would be punished—and that effectively shut Snookums up. He couldn’t talk without violating the First Law.
“Unfortunately, the killer couldn’t get Snookums to do away with me. Snookums knew perfectly well that an angel can blast anything at will—through the operation of God. Witness what happened at Sodom and Gomorrah. Remember that Snookums has accepted all this data as fact.