Dorian leads Basil to the school-room, which contains the picture, and instructs him to look behind the curtain covering the painting. Basil is reluctant to move the curtain, so Dorian does it for him. Basil is horrified by what he sees, at first not recognize the painting as his own work. Dorian's picture is of a horrible old man and only by finding his own signature on the painting, does Basil finally admit the painting is his own.

He still is not sure what the picture represents, so Dorian explains to him how the wish he made the day the painting was finished, has come to fruition. Basil realizes all the rumors he has heard about Dorian are true. He tells Dorian, he and Dorian must pray for forgiveness of their sins to purge them of this curse. Dorian is not willing to do as he says, instead he feels it is too late for forgiveness. He is filled with hatred for Basil and cannot stand to be around him any longer.

In a moment of rage, Dorian finds a knife, he had left in the room, and he plunges it into Basil. He repeatedly stabs him until he is sure Basil is dead and then he goes about the business of covering up his deed. He locks Basil's body in the room, stores his coat and bag in a hidden cupboard, replaces the lamp he brought upstairs with him, and goes outside to be let in by his servant. This is done in an effort to establish an alibi for himself. The valet had let Basil into the house earlier in the evening and saw him out of the house at eleven. He does not know Dorian and Basil returned to the house, so when he lets Dorian back into the house at 2:10 in the morning, he is able to give Dorian an alibi. Since Basil is supposed to be in Paris for six months, Dorian hopes no one will notice he is missing.

Dorian awakes the next morning, after having slept well, to slowly remember the events of the preceding night. He is still filled with hatred towards Basil and now he is trying to decide how to dispose of the body.

He remembers his former close friend, Alan Campbell, is a chemist. Even though he and Alan had at one time been inseparable, now they do not speak to one another. Dorian writes two letters, one is taken to Alan by Dorian's servant, the other Dorian keeps in his pocket. He is in agony waiting to see if Alan will come and help him with his problem.

Finally, Alan arrives and Dorian tells him of the body in the room upstairs. He tells Alan, Basil has committed suicide. He explains he wants Alan to make the body disappear, it seems Alan has worked on cadavers and he knows how to accomplish this task. Alan insists he will not help Dorian, because his work is for scientific discovery and not to help dispose of unwanted bodies. Dorian lets Alan know he has a letter in his pocket which could cause great him great harm, if mailed. He confesses to Alan he murdered Basil. Alan reluctantly agrees to help Dorian.

After acquiring the necessary items from his lab needed to dispose of the body, Alan and Dorian enter the room containing Basil's body. Dorian is agitated to see blood on the hands of the portrait of himself. He had forgotten the night before to hide the picture. He covers the picture and returns downstairs to wait for Alan to finish the job of disposing of the body. After he is done, Alan severs all ties to Dorian telling him he never wants to see him again.

That same evening Dorian attends a dinner at Lady Narborough's home. He does not want to be there, but feels it is necessary to continue his life as if nothing has happened. He is glad to see Lord Henry at the party and Lady Narborough is a good hostess. He is out of sorts throughout the meal and he hardly eats any food. This brings unwanted attention to himself from Lady Narborough and Lord Henry, they want to know what is bothering him. He tells them he is tired.

Lord Henry asks Dorian what he did the night before, after he had left him at eleven. Dorian is nervous and is not able to come up with a very convincing lie. First he tells him he went to the club, then he says he went for a walk, finally he settles on saying he has forgotten what he did. He goes overboard in giving Lord Henry a detailed description of when he arrived home. He goes so far as to tell Lord Henry he can ask his valet what time he returned home.

Dorian decides to leave the party early and returns home. At home, he takes Basil's coat and bag to the fireplace and burns them. He notices in his Florentine cabinet a box with a green paste wax. This fills him with a desire to go to the downtrodden side of London. He finds a driver to take him there.

Dorian has committed murder. He kills Basil, after showing him the effects his lifestyle has had on the painting. He, instead of being filled with remorse, is filled with terror over the prospect of being caught and tried for his crime. He blackmails a former friend and then indulges himself in a trip to the poor side of London.