The Old Man tells the Student that the dead man, the Consul, used to be charitable to the poor sometimes. He then asks the Student to push his wheelchair into the sun so that he can warm up. He extends his hand to the Student, who takes it and is shocked by how cold it is. "I have an enormously long life behind me, enormously long. I have made people unhappy and people have made me unhappy—the one cancels out the other—but before I die I want to see you happy. Our fates are entwined through your father—and other things," the Old Man says, refusing to let go of the Student's hand.
Finally, the Old Man lets go as the Girl, the Colonel's daughter, approaches, "though the audience cannot yet see her." They each admire how beautiful the Girl is, and the student talks about how lucky the man who marries her will be. The Girl enters wearing an English riding habit, and goes to talk to the Caretaker's Wife, before going into the house. When the Student mourns the fact that he has no hope of ever seducing the Girl, the Old Man tells him that if he serves him he will give him some power.
"Am I to sell my soul?" the Student asks, but the Old Man insists that he has no heirs and would like to give the Student his wealth when he dies, if the Student agrees to perform some tasks for him. First he must go to the opera, and then go to the Round Room that evening. The Student asks if the Old Man has had an eye on him for a while, and the Old Man admits that he has. He tells him to look up at the balcony, where the maid is putting the flag at half mast for the Consul. Then, the Girl waters some hyacinths. "Is she not like that blue hyacinth herself?" the Old Man asks. "She gives them drink—nothing but pure water, and they transform the water into color and fragrance."
The Colonel enters and shows the Girl the article about the collapsed house and the Student's heroism. As the sky begins to cloud over, the Old Man worries that it's going to rain, as the Fiancée closes the window. Suddenly, the Dead Man comes out the door, wrapped in a winding sheet. Only the Student can see him, and he narrates what he sees to the Old Man: the ghost looks up at the flag, then turns the corner to check on the poor outside his house.
The Old Man tells the Student, "Between ourselves he was a great scoundrel...When he knew his end was near, he cheated the State out of 50 thousand crowns." Johansson, the Old Man's servant, enters and reports to the Old Man, but the audience cannot hear him. As he notices that the Aristocrat is coming, the Old Man tells Johannson to wheel him around the corner so he can hear what the poor are saying, and tells the Student to stay put.
The Aristocrat, wearing mourning, walks on and talks to the Dark Lady, inaudibly. Left alone with Johannson, the Student asks him to tell him more about the Old Man. "He has been everything," Johannson says, adding, "It's power he wants. The whole day long he rides round in his chariot like the god Thor himself...The miserable cripple was once a Don Juan—although he always lost his women." Johannson explains that the Old Man is ruthless and that he "steals human beings." "He literally stole me out of the hands of the law...he turned me into a slave," Johannson says.
Hearing this, the Student decides that he should leave, when suddenly the Girl drops a bracelet out the window. The Student goes and retrieves it to return to the Girl. Afterwards, Johannson tells the Student that it will not be as easy to get away as the Student thinks, now that he is in the Old Man's clutches.
The Student asks Johannson if the Old Man is afraid of the Milkmaid, and Johannson seems to confirm this. When the Student asks Johansson what the Old Man is doing, Johannson tells him, "Listening to the poor. Sowing a little word, loosening one stone at a time, till the house falls down—metaphorically speaking...You see I'm an educated man. I was once a book-seller."
The Student decides not to leave, citing the fact that the Old Man once saved his father. Johannson notes that the Old Man is now talking to a policeman, as "he is always thick with the police." Suddenly, the Old Man enters, standing up in his wheelchairs, accompanied by a group of beggars. The Old Man sings the Student's praises for being heroic at the collapsing house. The maid hoists the flag to the top, and the Girl waves her handkerchief. "...Although I am not a Sunday child, I have the gift of prophecy and also that of healing. Once I brought a drowned person back to life. That was in Hamburg on a Sunday morning just like this..." the Old Man exclaims.
The Milkmaid enters, seen only by the Old Man and the Student, then holds up her arms like she is drowning, and stares at the Old Man, who becomes frightened and tells Johannson to wheel him away.
The play is about ghosts, the breaching of the boundary between the mortal and spirit world, but it is not exactly a fantasy or a science-fiction play. Rather, it is a surreal play that layers the metaphysical world on top of the material world in a more mysterious and ineffable fashion. The stage itself becomes a kind of threshold between the real and the unreal, a place in which ghosts and humans can communicate, and where echoes of the past can continue to reverberate in the present.
Part of what keeps the play in a strange liminal reality is the fact that the characters are unnamed. Rather, they are identified by their role or by their appearance, which turns them into archetypes. Instead of being a specific young man, we are introduced to the Student, who represents the young and impressionable attributes of that designation. Other characters include the Old Man, the Girl, the Milkmaid, and the Colonel. This turns all of them into representations of themselves, one step removed from reality, neither ghost nor mortal.
In this section, a sort of Faustian arrangement opens up between the Student and the Old Man. While the Old Man insists that it is no such arrangement, he enlists the Student to perform tasks for him in exchange for making him his heir, which would turn the poor Student's life around. In a matter of moments, the Student's prospects open up in unthinkable ways, but he does not yet know the price.
The Student is the closest thing we have to a protagonist, in that he is nearly as confused about the mysteries of the stage world as the audience. He is an innocent in the clutches of the Old Man, and is unable to tell if the Old Man is a friend or foe. Making matters even more complicated is the fact that the Student is able to see ghosts, which throws his sense of reality out of balance. He must pursue prosperity and clarity in a confusing and convoluted world that seems determined to bewilder him further.
The Ghost Sonata follows a very strict logic that is entirely unusual to Strindberg's vision of the world he has created. Events and characters rarely make any literal sense, but instead follow a kind of poetic logic that is not entirely recognizable or legible in a rational world. This is what makes the play such an important text in the history of modernist drama, a movement that privileged innovation and a rejection of tradition in favor of new forms and a less literal depiction of the world.