They discuss Tekla's first husband. Adolf has never seen him, but knows that he is an idiot, for Tekla has written a book in which the ridiculous man is described. Gustaf shows Adolf that he is treated as the second idiot by Tekla. He asks why Tekla sent away her child. Adolf hesitates to tell his friend, then confesses that at the age of three the child showed a likeness to the first husband which Tekla found unendurable. Gustaf asks Adolf if he has never felt jealous of the first husband. "Would it not nauseate you to meet him when out for a walk, when his eyes on your Tekla would say to you: We instead of I--We?" Adolf admits that the thought has haunted him. Gustaf draws a picture of the torment caused by the indelible memory of the third. "But they know that _one_ sees them in the darkness--and then they are frightened and in their fright the figure of the absent one begins to haunt them, to assume dimensions, to change until he becomes a nightmare disturbing their sleep of love, a creditor who knocks at the door, and they see his black hand between theirs, they hear his grating voice in the silence of the night which should only be disturbed by their beating pulses. He does not prevent their union, but he disturbs their happiness. And when they feel his invisible power of disturbing their happiness, when at last they flee--but flee in vain from the memory which persecutes them--from the debt they have left behind, and the judgment which frightens them, they lack the strength to bear their transgression and find a scapegoat which must be slaughtered...." Tortured by the suggestion that Tekla has now been unfaithful to him, which every sentence spoken by Gustaf drives more deeply into the inflamed brain, Adolf consents to test Tekla's fidelity by means devised by Gustaf. When she comes home Adolf is to study her manner, and lead her to reveal her real self, whilst Gustaf listens in another room. When the husband has reached the limit of his power of deduction he is to go out, and leave to Gustaf the rôle of inquisitor. Adolf is to be a secret witness of the second examination. He can hear all in the adjoining room. Tekla comes home. She is playful, loving, treats him as her naughty child--just as Gustaf said she would, if guilty. She has enjoyed herself, and Adolf's solemn tones of reproach and impending disaster cause a revulsion of feeling, in which she shows herself as the heartless coquette, the _mangeuse d'hommes_, to whom conjugal monotony is insupportably dull. Adolf goads her vanity by saying that she has reached the age, when admirers are no longer troublesome. She wishes to assure him of the contrary, warns him, threatens that in future he will have to play the ridiculous part of the jealous and deceived husband who, lacking evidence, can only injure himself.