While Dysart listens to the tape recorder on one side of the stage, Alan narrates the message on the other. He begins to discuss his experience on the horse at the beach when he was a child. He adoringly describes the feeling of being on it, the power beneath him, the sweat on the horse's neck and the warmth. From that point on he could not take his eyes off of a horse whenever one appeared, and spent a long time just watching their skin.
He thinks this fascination started with either the Prince horse book his mother read to him, or from hearing about the white horse in the Bible Book of Revelations. He also expresses his distaste for the type of "equitation" his mother likes, when people dress up the horses and ride them. He has more respect for cowboys, who are free, and wishes he were one. As Dysart is listening to the tape, the nurse comes in and interrupts; Frank Strang is here to see him.
Frank mentions that his wife does not know he has come. He tells Dysart about something he witnessed; in his room one night, Alan stood chanting things like "Prince begat Prince! Prance begat Prankus!" in front of the photograph of the horse. He ended with the words, "Behold—I give you Equus, my only begotten son!" The word "equus" stirs a memory in Dysart's mind, and he realizes that this is the "Ek" that Alan has been shouting in his sleep. To finish the ritual, Alan took a piece of string out of his pocket, made it into a noose, and put it in his mouth. Then he began to beat himself with a coat hanger.
Frank insists that religion is at the bottom of all of this. He never mentioned witnessing this incident to anyone else, since he cannot speak about it. Right before he leaves, Frank also drops one other clue—the night Alan committed the crime, he was out with a girl. He will not say how he knows this, but he tells Dysart to ask Alan about it.
Another session with Alan begins. Dysart asks who introduced him to the stables; Alan says it was someone he met at the electronics shop where he worked, Bryson's. Alan and extras onstage act out a scene between Alan and customers in this store as Alan continues to tell the story.
Jill Mason, a girl in her early twenties, comes into the shop. She asks for blades to clip horses, and Alan recalls seeing her at Dalton's stables. Jill remembers him, too, as the boy who always stares into the stable yard. She asks him if he is looking for a job, and mentions that he might be able to work at the stable on the weekends.
The scene begins with actors playing horses dancing around Alan on his first day at the stables. Mr. Dalton show him the ropes of his new job, and once Dalton leaves, Jill shows Alan how to groom the horse named Nugget, who is her favorite. She lets him try, and then leaves him alone with the horses. He is in ecstasy as he touches them, runs his hand along their skin. Dysart recognizes his excitement, and then asks him if he liked the girl, Jill, too; Alan is much less enthused. Just as Frank suggested, Dysart asks Alan if he took Jill out on a date—this makes Alan angry, and he accuses Dysart of being nosy just like his dad.
Later on, Dysart apologizes for pressing; Alan decides that it is his turn to ask Dysart questions. Once again, he asks about Dysart's wife, and reveals all the information he knows about her: she is a dentist named Margaret. He begins to pound Dysart with personal questions about her, notably asking if they ever have sex. Dysart has no patience for this and banishes Alan from the room, then enters into a furious monologue about Alan, calling him wicked and yet noting how perceptive he is of Dysart's own insecurities.
The choice of how to represent horses in this play is extremely significant. Rather than use real horses, build horse models, or even create full horse costumes, the playwright chose to keep the actors playing horses distinctly human, with only a mask above their head indicating what they are supposed to be. This is more than just a technical decision; to Alan, these horses are almost human. They have a humanlike significance in Alan's life, and the bodies onstage visually represent this.
These horses' humanity is taken even further through Alan's clear physical attraction to them, which is easy to interpret as sexual in nature. Alan is deeply moved by the physicality of the horses he encounters, his attention always trained on minute physical details like the sweat dripping from their skin. His excitement is aroused by the sensation of touching them on his first day in the stables. Dysart quickly recognizes the sexual nature of this attraction and tries to explore it further in his session with Alan. This attraction to horses is juxtaposed with Alan's lack of attraction to Jill, to whom, according to societal standards, Alan is meant to be attracted.
This play explores psychological and societal ideas of "madness," or what it means to have desires, thoughts, and behaviors different from what is deemed the norm. The famous psychoanalyst Sigmund Freud postulated that much mental instability stems from early childhood experiences. While most of Freud's theories are no longer considered valid, Alan's situation seems to follow this pattern; his fixation on horses stems from his first experience on a horse as a child, as well as from many other childhood influences such as the Bible and the Prince story.
The chanting that Frank observes in his son's room refers to the Biblical Book of Genesis, which outlines the genealogy of humanity beginning with Adam, going on through his sons and the sons of his sons. Alan repeats this process referring to the horses he has come to view in the same light as these religious figures, emphasizing the spiritual value they have in his mind. The line "Behold—I give you Equus, my only begotten son!" confirms that the horse has become a Christ-like figure to Alan.
The institutionalization of their son, rather than unite them in solidarity, has only driven Frank and Dora further apart. Over the last two sections, each has come to talk in secret to Dysart and implicate the other for influencing Alan's crime. This entire case is about figuring out where to place the blame; the purpose of Alan seeing Dysart in the first place is so that he can lift the blame off of Alan's shoulders alone and figure out where else it should be placed. Neither parent believes that they are deserving of blame, and this has served to pit them against each other in secret.
The tension in their relationship highlights the tension in Dysart's own relationship with his wife, which Alan has been perceptive enough to pry him about. Though we do not fully know why, Dysart is dissatisfied with his barren life, including his marriage. Some of this tension appears to do with a budding intimacy between Hesther and Dysart; though it has yet to become anything significant, the manner in which the two interact suggest an attraction. Hesther is the kind of stability and sensibility that Dysart does not feel that he has in his life.