A while later, the laborers unknowingly enter the glade where Titania sleeps to rehearse their play. Before they start, Bottom states his concern that parts of their play are problematic. For instance, he thinks the ladies will be upset when Pyramus kills himself with his sword. Starveling says they should leave the killing out entirely, but Bottom proposes another solution: they could write a prologue in which they explain that no one really gets hurt, and further that Pyramus isn't really Pyramus, but Bottom. Quince agrees. Snout, meanwhile, thinks the ladies will also be afraid of the lion. Bottom solves that problem too: half of Snug's face should show through the lion's mask, to make it clear he isn't a real lion. Snug should also announce that he's Snug and not a real lion.
Through the laborers continuing fear that audience's will take their acting for reality, Shakespeare points out the true magic of theater. The audience watching Midsummer laughs at Bottom's belief that the Duke and his ladies won't be able to see through his acting. But the audience is laughing because Bottom is so dimwitted. In other words, the audience is laughing because it's judging Bottom as if he was a real person, not an actor.
The laborer's next theatrical dilemmas are how to make sure there's moonlight on the stage since Pyramus and Thisbe meet by moonlight, and how to get a wall onstage, since Pyramus and Thisbe are separated by a wall. They agree they should have one actor carrying a lantern play moonlight and another covered with plaster play a wall.
The laborers continue to be incredibly simpleminded and literal about their play. They don't trust that an audience can just imagine that there's moonlight; they have to get someone to play moonlight.
Meanwhile, Puck, invisible, enters. Puck is amused by the laborers' constant mistakes, and decides to stay and watch, and be an "actor too, perhaps, if I see cause" (3.1.68).
Puck is about to stage a "play" of his own.
The laborers begin to rehearse, mangling their lines (substituting "odious" for "odorous") and missing their cues. The play calls for Pyramus to exit at one point, and Puck follows Bottom offstage. When Bottom returns, his head has been replaced by the head of an ass (donkey). Terrified, the other laborers run. Puck transforms himself into various beasts and chases them. Bottom, who thinks his friends are pretending in order to scare him, decides to show he isn't frightened by staying in the glade and singing.
Aided by magic, though, Puck's play really does blur the boundaries between fiction and reality. Puck's play is like a dream, in which wild, supernatural things happen that the laborers can neither control nor comprehend.
Titania wakes at the sound of Bottom's voice. She begs Bottom to continue singing and tells him that she loves him. Bottom is dumbfounded, though he notes, "And yet, to say the truth, reason and love keep little company together nowadays" (3.1.129-130).
Even the self-important Bottom can tell that it makes no sense for Titania to love him. But his observation about love's irrationality can stand for the whole play.
Titania tells Bottom he must stay with her in the woods whether he wants to or not, because she loves him. She orders four fairies—Peaseblossom, Cobweb, Moth, and Mustardseed—to wait on him and bring him jewels, exotic fruits, and to lead him up to her sleeping bower.
Here is another of love's less than pretty side-effects: jealousy. As the more powerful member of this couple, Titania attempts to completely control Bottom.