In A Midsummer Night's Dream, Lysander tells Hermia, “The course of true love never [did] run smooth” (1.1.134). And to illustrate this thematic principle, Shakespeare devises multiple plot lines within this one play.
The primary narrative tells of the misadventures of a human love quadrangle. Hermia and Lysander wish to be married, but Demetrius wishes to marry Hermia and has been promised this union by her father. Helena is desperate to win the affections of Demetrius, who insults her whenever possible. Thus, the humans find themselves in situation ripe for drama as they all flee into the woods.
Running parallel to this plot line is the world of the fairies. Titania and Oberon are at odds, and Oberon calls upon Puck to use a magical potion to cause Titania to fall in love with the first animal she sees. After some comedic misadventures, Puck places the magic potion in Lysander's eyes, and the first person he sees upon awakening is Helena. This complicates the human situation even further.
Fairy world and human world are interwoven throughout the play as the humans and Titania fall under the spells of love potions. For most of the play, members of both worlds are confused and operate from a false sense of reality. This underscores one of Shakespeare's most famous lines in this poem: "The course of true love never did run smooth" (I.i.134).
There are two parallel plot frames in A Midsummer Night's Dream. The first takes place among the human mortals; the second, among the fairies.
The humans have much love activity going on. Theseus and Hippolyta will be married soon; there's has been a tempestuous courtship between Hippolyta, the queen of the Amazons, stolen as an unwilling (but now reconciled) bride, and Theseus. In the parallel plot among the faeries, Theseus and Hippolyta's counterparts, Oberon and Titania, king and queen of the faeries, have been quarreling over a young Indian boy that both want in their retinue. Their quarrel has caused bad weather in the mortal world.
In the human plot, Lysander and Hermia, who are in love, run away to the woods, followed by Demetrius (who loves Hermia) and Helena (who loves Demetrius). Meanwhile, a group of lower-class men preparing a play for the upcoming wedding also stumble into the fairies' forest realm. The two worlds—human and faerie—collide in the forest, and after many comic mishaps and the intervention of the faeries, all works out to a happy ending.
The primary plot in "A Midsummer Night's Dream" by William Shakespeare is the love triangle, or quadrilateral, between Helena, Hermia, Lysander, and Demetrius. Shakespeare uses two frame narratives, or sub-plots, to help shape this story. The first frame narrative is the plot around the faeries. Titania, Oberon and Puck influence the young lovers in the forest. The other frame story, who perform for the lovers, is the group of amateur actors rehearsing a play.
Shakespeare uses the frame narrative in many of his plays, presumably to hold the audience's attention for longer periods of time. Interestingly, some of the frame narratives he uses end up being abandoned. One example of this is the frame story used in "The Taming of the Shrew".
The narratives in "A Midsummer Night's Dream" are successful in moving the plot and creating more interest in the characters and themes.