We are in Seville at the end of the 16th Century. Miguel de Cervantes, failed poet, playwright and actor, has been arrested by the Inquisition "For offenses against his Majesty's most Catholic Church." We meet him as he is thrust into the prison's "common room," together with his manservant, to await trial. The "common room" is populated by criminals of all stripe, headed by the biggest bully of all, whom they call "The Governor." Immediately a kangaroo court is assembled, its aim to confiscate all of Cervantes' possessions.

Cervantes pleads to keep one package which seems crucially important to him. The Governor, tearing it open, says, disgustedly, "Paper." "Manuscript!" cries Cervantes. When the disgusted Governor proposes to throw it into the fire, Cervantes stops him, demanding a trial, and proposes to offer a novel defense in the form of an entertainment. . . a charade, if they please. "At worst if may beguile your time." He asks the prisoners to enter in and to play whatever roles may appeal to them.

He begins making-up, speaking winningly as he does so. "I shall impersonate a man," he says. "Come-enter into my imagination and see him. His name is Alonso Quijana... a country squire ...no longer young...bony, hollow faced ...eyes that burn with the fire of inner vision." He continues: "He conceives the strangest project ever imagined-he will become a knight-errant and sally forth into the world to right all wrongs." Now he becomes his invented character, Don Quixote.

Don Quixote and Sancho mount their "horses" and ride forth to the brave music of MAN OF LA MANCHA. To Sancho this Highway to Glory looks like the road to El Toboso where you can buy chickens cheap, but the Don informs him that, "Like beauty, my friend, `tis all in the eye of the beholder." He warns Sancho of his enemy, The Great Enchanter, whom one day he will meet in final battle.

They encounter windmills, which Quixote is convinced are giants. He attacks-disastrously. Undaunted, by this setback, he and the pragmatic Sancho head for an inn which, typically, Quixote insists is a castle.

At the inn are rough men; muleteers. And rough women, particularly a kitchen slavey and part-time prostitute called Aldonza.

To the Muleteers who make crude advances to her, Aldonza sings the contemptuous, "IT'S ALL THE SAME."

Quixote enters; he sees the muleteers as knights like himself, which bemuses them, and is thunderstruck at his first sight of Aldonza. "Sweet lady ...fair virgin..." he addresses her, and in song (DULCINEA) calls her by another name. Aldonza is equally bemused; is this eccentric merely making fun of her?

The scene reverts to the prison where Cervantes now calls attention to Quixote's family and friends who are in deep distress at the master's behavior. There's the Don's niece, Antonia; her fiancee, the pedantic Dr. Carrasco; the baleful Housekeeper; and his good friend, the gentle Padre Perez. All are worried about the effect Quixote's madness will have upon' their lives, and they sing the hypocritical, I'M ONLY THINKING OF HIM. Led by the rationalist Dr. Carrasco, they decide to pursue the man who calls himself Don Quixote and to persuade him to return home.

At the Inn, Quixote is languishing for love of his newly-discovered Dulcinea. He sends Sancho to her with a "missive." Aldonza derides Quixote's florid sentiments, and demands to know why Sancho follows him. Fumbling for reasons, Sancho can only come up with the simple, I REALLY LIKE HIM. Aldonza rewards him with a "token" to be delivered to his master-a filthy dishrag. But Aldonza is troubled ...while feeding the horses, she talks to them, and she sings, WHAT DOES HE WANT OF ME. The Muleteers, heckling her as she goes about her duties, sing a lascivious song, LITTLE BIRD, making fun of her and her "knight."

A Barber enters, cheerily pitching his profession (BARBER'S SONG) and encounters Quixote who sees the Barber's brass shaving basin as a magical helmet of gold. "When worn by one of pure heart," says Quixote, "it makes him invulnerable to all wounds." He demands that the Barber turn it over to him. The Barber, intimidated, crowns Quixote with the "helmet", to which is attached Aldonza' a dishrag-token, and Quixote and the ensemble sing THE GOLDEN HELMET OF MAMBRINO with heartbreaking sincerity.

Dr. Carrasco and the Padre have arrived and are watching with clinical interest. "There is either the maddest wise man or the wisest mad man in the world," observes the Padre. Carrasco insists that he is mad, and they must find a cure. "The cure," says the Padre. "May it be not worse than the disease." And he sings the wistful, TO EACH HIS DULCINEA.

Quixote asks of "The Lord of the Castle" (the Innkeeper), that he be officially dubbed a knight, and the Innkeeper agrees. He will dub him at dawn, after Quixote has held vigil in the proper manner. Quixote is delighted. During his vigil he is accosted by Aldonza who is on her way to a sexual rendezvous with Pedro, the head muleteer. Aldonza demands to know why he does these things. "I hope to add some measure of grace to the world," replies Quixote. And when pressed further, adds, "It is necessary to follow the quest." Aldonza demands, "What does it mean, quest?" and Quixote replies, "The mission of each true knight. His duty-nay, his privilege." And he sings, THE IMPOSSIBLE DREAM.

Pedro, angry that Aldonza's kept him waiting, strikes her, and Quixote, outraged, attacks Pedro who calls for help from the other muleteers. A full-scale battle results, and the muleteers are routed by Quixote and his forces of Aldonza and Sancho. The Innkeeper deplores the trouble, but is reminded of his promise to dub Quixote knight. "Oh, certainly," says the Innkeeper. "Let's get on with it." And he does so. (THE DUBBING.) But Quixote, unsatisfied, claims that it is customary to grant the new knight an added name. The Innkeeper inspects Quixote's battered face and sings, KNIGHT OF THE WOEFUL COUNTENANCE. Aldonza, admonished to "minister to her enemies' wounds," tries to do just that, but is beaten and abducted by the muleteers, unknown to Quixote.

Quixote and Sancho, on the road again, encounter a thieving band of Gypsies who rob them of all their possessions, whereupon they must return to the inn. Aldonza, too, returns, terribly beaten and bruised, furious at being trapped by Quixote's "madness and lies." Bitterly, she sings ALDONZA, a recitation of her disastrous life. She is interrupted by the sound of trumpets and the entrance of an amazing figure, The Knight of the Mirrors, with his retainers. Quixote sees him as The Enchanter, his mortal enemy. He challenges him and they fight, but Quixote is blinded by multiple mirrors that show him as he really is-a demented old man. He is defeated.

The Knight of the Mirrors unmasks-it is Dr. Carrasco.

Back in the prison, a Guard warns Cervantes that shortly he will be summoned to appear before the Inquisition. Cervantes pleads with the prisoners for time to finish his story. It's granted; he will improvise an ending.

In the home of Alonso Quijana, the man we knew as Don Quixote is dying. Sancho comes to visit, and reluctantly is allowed to. He sings A LITTLE GOSSIP. Aldonza demands admittance, though it is opposed by the Quijana family. But she bullies her way in. Quijana does not recognize her nor remember her name. "Please," she pleads, "try to remember." She tells him that he called her by another name, and sings a reprise of DULCINEA.

Qauijana's mind stirs. "Then perhaps it was not a dream..." Aldonza responds: "You spoke of a dream." As she quotes the words, Quijana/Quixote remembers, THE IMPOSSIBLE DREAM. But his strength fails, and he sinks down, dying. The Padre prays for his soul in THE PSALM.

Aldonza urges Sancho to believe in the dream. Transfigured, she says, "My name is Dulcinea." In the prison the drums of the Inquisition are heard as the guards come to fetch Cervantes for his real trial. The Governor hands Cervantes his precious manuscript, saying, "I believe that Don Quixote is brother to Don Miguel."

"God help us," replies Cervantes, wryly, "we are both men of La Mancha." The prisoners sing a finale, THE IMPOSSIBLE DREAM, to lend Cervantes courage as he mounts the stairs.