The artisans meet in the wood for their rehearsal. Bottom is convinced that their play will be so well produced that the ladies in the audience will be shocked by the contents of it. For example, Pyramus must kill himself. To solve the problem of adverse audience reaction, he asks that a prologue be written, explaining that Pyramus does not really die. He also feels the need to have it explained that Pyramus is in fact not Pyramus at all, but Bottom the weaver. But then, what of the lion? Won't the lion scare the ladies too? asks Snug. Bottom has the solution to that also. He tells Snug to inform the audience that he is not really a lion, but Snug the joiner. So literal-minded are the artisans, they then decide that since Pyramus and Thisbe meet by moonlight, there must be a character to represent moonlight, and also another character to represent the wall through which the lovers talk.
The rehearsal begins, as Puck watches. Bottom as Pyramus and Flute as Thisbe make some howling errors that Peter Quince has to correct. Then Bottom, who has temporarily left the scene, returns, but the mischievous Puck has caused his head to be transformed into an ass's head. Most of the artisans flee in terror, and Puck goes with them, promising to chase and torment them. Then Snout and Peter Quince see the ass's head on Bottom, and they run too.
Bottom, suspecting that his companions are trying to make an ass of him, decides to sing to himself. The song awakes Titania, who immediately sees Bottom and falls in love with him. Bottom, of course, does not have a clue as to why this has happened. Titania asks him to remain with her in the wood; she will have him attended and cared for by her fairies. She summons Peaseblossom, Cobweb, Moth and Mustardseed, and tells them to lead Bottom to her bower.
The artisans' obsession with obtaining realism in their play is connected to a wider theme of the play: the contrast of reason and imagination. Peter Quince and company misunderstand the nature of theater, which is more an imaginative than a realistic art.
The theme of the irrationality of love recurs in the absurdity of the affair between Titania and the ass-headed Bottom. As Bottom says, "reason and love keep little company together nowadays."