"Tell us all about Dagger!" That was the command thrown at Napoleon Solo and Illya Kuryakin by the unseen THRUSH agents who kidnapped and interrogated them with lie detectors. And from each U.N.C.L.E. agent came the same answer: "We know absolutely nothing of DAGGER." "You appear to be telling the truth," said the hidden voice. "A pity..." But it was more than merely unfortunate that the U.N.C.L.E. organization had never heard of DAGGER. For the secret behind that name was an insane plot for mass murder - the murder of the human race.