It all starts with four lovers. Lysander lover Hermia, Hermia loves Lysander, Helena loves Demetrius, Demetrius loves Hermia. Hermia's father wants her to marry Demetrius, and she is given four days to choose between Demetrius, life in a nunnery, or a death sentence. Hermia chooses to run away with Lysander to the forest.
Meanwhile in the forest, Oberon and Titania, the king and queen of the fairies, are fighting over a boy that Titania has adopted. Oberon sends Puck, his servant, to receive magic love drops, to sprinkle on Titania's eyelids, so she will fall in love with the first thing she sees.
Meanwhile, Demetrius and Helena follow Lysander and Hermia into the forest. Oberon overheard Demetrius announcing his love for Hermia to Helena. He took pity on Helena, and asked Puck to put magic love drops on Demetrius. By accident, he put them on Lysander, and Helena ran into him, and he fell in love with her when she woke him up.
On his way back, Puck sees a group of craftsmen rehearsing a play for the Duke's wedding. Playfully, he gives one of them, Bottom, the head of a donkey. Oddly enough, he happens to be the first thing Titania sees when she wakes up, hence, she falls in love with him.
Oberon is having fun with the magic love drops, but he is unimpressed when Puck fails to get Demetrius and Helena together. Oberon puts the drops on Demetrius himself and insures that Helena is the first one he sees. But Helena is feeling she is being mocked by Lysander and Demetrius.
Finally, Oberon decides to put things back to normal. He puts the antidote for the love drops on Lysander's eyelids, so he will be in love with Hermia again. He puts the antidote on Titania's eyelids, so she will be in love with him again.
Someone discovers the couples in the forest and they all return to the town together, and have a feast and talk over their "strange dream".