Act One

As the overture begins, the Mute enters, sees the audience and gestures to the other players to join him on the platform upon which the show will be played. A tattered drape, which is lettered "The Fantasticks" hangs at the front of the platform. At stage right, there is a large box of theatrical props. The rest of the cast listens as El Gallo sings "Try To Remember" to the audience, encouraging them to recall the tender Septembers of their youth.

El Gallo introduces The Boy, The Girl, their Fathers and the wall that separates them. He explains that The Girl began to notice a change in her ugly duckling features when she reached 15. Now 16, her sudden prettiness has led her to suspect that she is a princess. She relates how, when a bird woke her up this morning, she put on her mother's necklace and her eyes changed color ("Bird Magic"). She then pleads for a life that is beyond the everyday and full of magic ("Much More").

The Boy enters and declares his love for The Girl. A wall appears in the form of a stick held by The Mute. Their parents built it to keep The Boy and The Girl apart, but the young couple vow to be together, in spite of it ("Metaphor"). They discuss the risks that they have taken to meet at the wall, obviously savoring every moment of the danger. The Girl reports a dream in which The Boy saved her from being abducted by a band of scoundrels. In her dream, after her dramatic rescue, their warring fathers agreed to allow them to live happily ever after.

However, they are brought back to reality by the appearance of The Boy's Father in the garden. He threatens to make it even harder for the young couple to see each other. The Boy responds by insisting that he will only marry a girl of his own choosing ("I'll Marry"). He leaves as The Girl is joined by her father, who orders her inside.

The two Fathers embrace over the wall, revealing that they are really the best of friends and are only pretending to be enemies to deceive their offspring. They believe that, if their children think they want them to remain apart, they will be sure to come together. The Fathers are sure that their children would never have agreed to a prearranged marriage between them, explaining how to manipulate children ("Never Say No"). They are now searching for a way to end the feud and settle upon the notion of a planned abduction. Hucklebee has hired a professional abductor to do the job. He appears in the form of El Gallo.

El Gallo agrees that he will pretend to kidnap The Girl, allowing The Boy to save her. A battle will follow, which The Boy will seem to win. When the Fathers inquire about the cost, he replies that different charades can be contracted at various prices ("It Depends on What You Pay"). The Fathers leave to rehearse their parts in the charade as Henry, an ancient actor down on his luck, and Mortimer, an "extra" dressed in a loincloth and feather, are called forth from the prop box by El Gallo. Henry recalls his great performances of the past, and Mortimer demonstrates his special expertise at dying.

El Gallo hangs a wooden moon as the lights soften and become blue. A harp glissando is heard. The Girl and The Boy meet in a forest glen... in September... before a rainfall. He promises her a happy ending, and they pretend that the glen is their castle ("Soon It's Gonna Rain"). The Mute sprinkles them with paper rain.

Their idyll is broken when Henry, Mortimer and El Gallo pretend to attack them and attempt to kidnap The Girl ("Abduction Ballet"). Henry and Mortimer pretend that The Boy has mortally wounded them. The Boy and El Gallo do battle, and El Gallo simulates death in a highly dramatic fashion. The music becomes jolly and triumphant. The young lovers rush onto the platform and embrace. The Fathers rush in and embrace, as well. Henry and Mortimer disappear into the prop box. The lovers and Fathers sing "Happy Ending," striking a pretty pose. El Gallo ends the act by commenting on the difficulty of holding such a pose. He takes the moon and, as he exits, declares that it is time for the intermission.

Act Two

El Gallo returns with the moon, and The Mute lowers the front drape to reveal the lovers and their Fathers, still trying to maintain their tableau. El Gallo explains that "the play is never done until we've all of us been burned a bit and burnished by the sun." He reverses the moon and reveals the sun. The music grows more intense.

The group members break their pose and comment on the sudden heat. The Girl notices that The Boy looks different in the sunlight. He comments that he is not ready for marriage yet. The Girl dreams of doing something exciting. The Boy eyes the road out of town longingly. The Fathers begin to squabble about their opposing theories of gardening. They all sing "This Plum Is Too Ripe" and the cynic is replacing the scenic as the moonlight fades. The lovers miss the moon; the Fathers miss the wall. In irritation, Hucklebee reveals that the Fathers staged the abduction attempt to bring their offspring together.

The Girl declares that "we didn't need your moon or bandits. We're in love! We could have made our own moons!" The Boy is bitter to discover that they were nothing more than puppets. Bellomy is furious with Hucklebee for spoiling everything. The Fathers quarrel and set about building another wall. The Boy challenges El Gallo to a real contest. El Gallo easily disarms The Boy in front of The Girl. The Boy and The Girl battle and she slaps him. He decides to take the road out of town; she decides to take her hair down and go swimming in the stream. He threatens to find his madness; she threatens to have an affair. He goes.

The Boy sings "I Can See It," describing the world that he believes he will find. His lyrics are countered by those of El Gallo, who sings of the unpleasant surprises that are in store for The Boy. El Gallo sends him off to learn the truth, then releases Henry and Mortimer, who are dressed as pirates, to follow him ("An Episode").

The Fathers enter to supervise the work that The Mute is doing on their wall. Hucklebee says that he has heard nothing from his son, and Bellomy reports that his daughter wastes her days dreaming. They agree that their predictable gardens, unlike their children, are their solace ("Plant a Radish").

The Girl finds El Gallo in a tree and calls him "her bandit." She shows him the spot where he bruised her arm during the supposed abduction. She has marked it with a ribbon. At her suggestion, El Gallo agrees to take her to see the world ("Round and Round"). For the trip, he gives her a mask that blots out any expression of compassion or horror. Her face is frozen in joy. As they "travel," they encounter The Boy in a series of increasingly wild situations. When The Boy is set on fire, beaten and forced to lie on a bed of nails, The Girl hides behind her mask, at El Gallo's prompting, and laughs.

The Girl and El Gallo return home. He tells her to pack and kisses her on the eyes. He promises to wait for her, but demands her most treasured possession – her mother's necklace – as a pledge that she will return. El Gallo assures her that the world really is as magical as he claims, and The Boy, who no one notices, echoes him ("Beyond That Road"). Realizing that El Gallo is about to break The Girl's heart, The Boy demands that the bandit not abandon her. Once again, El Gallo raises his hand to The Boy. The Boy falls back as if struck. El Gallo says, "Who understands why Spring is born out of Winter's laboring pain? Or why we all must die a bit before we grow again?" He leaves them alone.

Together again, with their newly discovered wisdom, The Boy and The Girl admit their true feelings for each other ("They Were You"). As they begin to understand the truth of what they both have endured during their separation, they shelter each other from the snow that begins to fall. The Fathers appear and announce that they are taking down the wall. El Gallo admonishes them to "always leave the wall." He reprises "Try to Remember" and helps The Mute to hang the front drape on the platform, ending the show.