Or was it because she wanted to shield the real killer? Maybe she was a friend of Naia North's and had known the blonde girl was in Gilmore's laboratory all along. She might even have deliberately steered everyone out of her office after Cordell discovered the bodies, making it possible for Naia to slip out unseen. It was a slender lead, but the only one large enough to get even a fingernail grip on. He drew the phone over in front of him and began a series of calls designated to give him more information about Alma Dakin. A call to the University took him through a couple of secretaries before he reached the right person. Her name was Miss Slife, personnel director of all non-teaching employees. Miss Dakin? Why, of course! A lovely girl and very dependable. She had come to the University in search of a position only a day or two before Miss Collins, Professor Gilmore's previous secretary, had resigned. Since Miss Dakin's references showed that she had worked for a short time as secretary to Dr. Karney, one of the co-discoverers of the atom bomb (according to Miss Slife), she had been engaged to take Miss Collins' place. Professor Gilmore, poor man, had been very pleased with the change and everybody was happy: Miss Collins at inheriting a vary large sum of money from a relative she'd never even heard of, Miss Dakin at being able to get such a nice position, and _dear_ Professor Gilmore at finding such a satisfactory replacement. When Miss Slife had run down, Kirk said, "This Dr. Karney. Why did Miss Dakin leave him?" The woman at the other end of the wire seemed astonished by Kirk's ignorance. "Why, I assumed _everybody_ knew about Dr. Karney. He died of a heart attack about eight months ago." "_What!_" "Goodness, there's no need to shout, Mr. Kirk. He was connected with Clement University, out in California, and suffered a stroke of some kind while at work." Kirk thanked her dazedly and broke the connection. This, he told himself, is too much a coincidence to _be_ a coincidence! Two prominent nuclear scientists dying suddenly within seven months of each other at opposite ends of the country--and both of them with the same secretary at the time of their deaths! A sudden thought sent him leafing rapidly through the trial transcript to the place where Paul Cordell had told of the disjointed phrases he claimed to have heard before he pushed into Professor Gilmore's laboratory. The words he sought seemed to stand out in letters of fire: "... three in the past five months...." * * * * *