"Here we have a suggestion on a means to control the thought processes of our catto. What we would like to do is to extirpate memory of his obstacle or problem. How to be selective? The obvious way is to attack one of the compounds, or its catalyst, at one or more synapses of the particular thought track. In order to be selective we choose a compound which is fugitive and which appears only during the process of thought transfer. I settled upon the substance Helmut and Gerard label heptant, because it has a highly definite chemical identity. The problem now is merely the formulation of a chelate which will weld to heptant, and remove it permanently from operative function. I farmed out the problem to Didactor Vauxine Tudderstell of the Maxart Bio-Chemical Clinic." Basil went to the cabinet, brought forth an orange bottle. "Here it is — anti-heptant. Water-soluble, non-toxic, highly effective. When it is present in the cerebral blood supply, it acts like the eraser button of a recorder, canceling whatever circuits are active, but inactive toward those not in use."