This paper's main thesis is that the profoundly destructive aspect of incest is located no less than in the act itself, in the language that accompanies it, which takes away (or makes it impossible to establish) the victim's very capacity to think. In the scene of incest, it is not merely the various openings of the body, but also the openings of thought that transform into evacuation or ejection holes or worse, holes for destructive invasion. The girl or the boy are barred from thinking, not only because the abusive scene imposes non-thinking, but because they experience thoughts as gaping holes that expose the child's mind to the danger of being invaded again and again. Clinical and literary vignettes illustrate two defensive positions arising from the malignant contact with the incestuous ambiguous language: One involves the overall flattening of three-dimensionality, layeredness and depth. The other is a defensive phallic position employing various modes of ejection by way of fending off penetration by the other's thinking. Finally the paper discusses the inherent ambiguity of the psychoanalytic scene and the conditions of possibility it offers for creating a therapeutic alliance in the case of incest victims.