“Don’t be too positive,” Nick replied. “The drug may have been administered without her knowledge.” “By whom?” “That’s the question. Possibly by Doctor Thorpe himself. Possibly by some one else, whose identity is not even suspected. There may be in connection with this affair, Clayton, various circumstances that we have not even dreamed of.” “That is possible, of course,” Clayton nervously admitted. “But I cannot imagine any circumstances consistent with such a theory.” “Don’t try to do so,” Nick replied. “Before undertaking to unearth the circumstances, Clayton, it will be better to find out positively whether I am right.” “Can that be done?” “I think so.” “How? By what means?” “Let me inform you,” Nick said, more gravely. “Scopolamine is a drug with which the majority of physicians are not very familiar. That may be why those attending her have not suspected that it figures in this case. It first came into modern scientific use within the present generation.” “How did you learn about it?” questioned Clayton. “That is not material,” smiled Nick. “I make it a point to learn all about everything that can be applied to criminal uses. That’s part of my business.” “I suppose so, after all.” “It is not necessary for me to enlarge upon the qualities of scopolamine, however, and its peculiar effects upon human organisms, particularly when used in combination with morphium,” Nick continued. “It is known to produce, when persisted in, a very complete state of amnesia, frequently causing absolute loss of memory during the period it is administered, together with other effects such as are observable in Madame Clayton’s condition. All this leads me to suspect the use of scopolamine in her case, possibly in combination with other ingredients, the subtle qualities of which are not generally known.” “How administered?” inquired Clayton. “By hypodermic injection.” “But who on earth, Carter, could have drugged my mother in that way? Surely no inmate of this house is guilty of such infernal deviltry.” “That’s an open question,” said Nick. “We will not undertake to answer it, Clayton until I am convinced that I am right. In the meantime, however, you must conduct yourself precisely as if no such suspicion existed. You must not betray it by word, look, or sign. You must not confide in your wife, even, until after I have taken the steps I have in view. In other words, Clayton, absolute secrecy is imperative.” “I see that point, of course, and will govern myself accordingly.” “Very good.” “But what are your plans? What steps have you in view?”