Hermia and her beloved Lysander have fled to the forest, as it's the only place where they can express their love for each other without fear. Hermia's father, Egeus, wants to marry his daughter off to Demetrius, but Hermia's not interested; she only has eyes for Lysander. Egeus is very much of the old school when it comes to parenting; what he says, goes. And if he wants Hermia to marry Demetrius, then as far as he's concerned, she jolly well will, whether she likes it or not. Besides, if Hermia persists in defying her father's wishes, under Athenian law she'll either be executed or end up in a convent. So off to the forest she goes with Lysander.
Thanks to the mischievous Puck's magic, the course of love between the two lovebirds doesn't go smoothly at all. For one thing, Lysander has fallen in love with Helena, because Puck mistakenly put a drop of magic flower on his eyes instead of on Demetrius's. Thankfully, Oberon intervenes and cleans up Puck's mess, and soon Demetrius is in love with Helena as originally intended. The problem, though, is that Lysander is still bewitched, so he joins Demetrius in the pursuit of Helena.
Puck makes amends for his earlier blunder by putting Hermia, Lysander, Helena, and Demetrius to sleep. He's placed an antidote on Lysander's eyes so that when he wakes up he'll no longer be smitten with Helena. However, trouble soon arrives in the shape of Egeus, who has finally managed to track down his errant daughter and her lover. He demands that Hermia marry Demetrius, but Demetrius, still under Puck's spell, remains head over heels in love with Helena. Theseus, the king of Athens, who has accompanied Egeus to the forest, overrules him and releases Hermia from her obligation to marry Demetrius. Hermia is now free to marry Lysander, the man she loves.