Oberon instructs Puck, his helper, to find a magic love potion and to give it to Lysander so as to make him fall in love with Hermia. However, Puck makes a mistake and because of it, both Lysander and Demetrius fall in love with Helena, which is not something Oberon wanted to happen.
Oberon sees how much Helena loves Demetrius so he instructs Puck, his fairy henchman, to find a specific flower to make a love potion and give it to the "Disdainful Athenian youth" Demetrius so he will fall in love with Helena when he wakes. Instead, Puck accidentally touches Lysanders eyes with the love potion, then later touched to Demetrius' eyes which then ends the story with two men being madly in love with Helena which is something Oberon did want.