Mrs. Alving, having made what her family called a most admirable match, discovers shortly after her marriage that her husband is a drunkard and a roué. In her despair she flees to her young friend, the divinity student Manders. But he, preparing to save souls, even though they be encased in rotten bodies, sends Mrs. Alving back to her husband and her duties toward her home.

Helen Alving is young and immature. Besides, she loves young Manders; his command is law to her. She returns home, and for twenty-five years suffers all the misery and torture of the damned. That she survives is due mainly to her passionate love for the child born of that horrible relationship—her boy Oswald, her all in life. He must be saved at any cost. To do that, she had sacrificed her great yearning for him and sent him away from the poisonous atmosphere of her home.

And now he has returned, fine and free, much to the disgust of Pastor Manders, whose limited vision cannot conceive that out in the large world free men and women can live a decent and creative life.

Manders. But how is it possible that a—a young man or young woman with any decent principles can endure to live in that way?—in the eyes of all the world!

Oswald. What are they to do? A poor young artist—a poor girl. It costs a lot of money to get married. What are they to do?

Manders. What are they to do? Let me tell you, Mr. Alving, what they ought to do. They ought to exercise self-restraint from the first; that's what they ought to do.

Oswald. Such talk as that won't go far with warm-blooded young people, over head and ears in love.

Mrs. Alving. No, it wouldn't go far.

Manders. How can the authorities tolerate such things? Allow it to go on in the light of day? (To Mrs. Alving.) Had I not cause to be deeply concerned about your son? In circles where open immorality prevails, and has even a sort of prestige——!

Oswald. Let me tell you, sir, that I have been a constant Sunday-guest in one or two such irregular homes——

Manders. On Sunday of all days!

Oswald. Isn't that the day to enjoy one's self? Well, never have I heard an offensive word, and still less have I ever witnessed anything that could be called immoral. No; do you know when and where I have found immorality in artistic circles?

Manders. No! Thank heaven, I don't!

Oswald. Well, then, allow me to inform you. I have met with it when one or other of our pattern husbands and fathers has come to Paris to have a look around on his own account, and has done the artists the honor of visiting their humble haunts. They knew what was what. These gentlemen could tell us all about places and things we had never dreamt of.

Manders. What? Do you mean to say that respectable men from home here would——?

Oswald. Have you never heard these respectable men, when they got home again, talking about the way in which immorality was running rampant abroad?

Manders. Yes, of course.

Mrs. Alving. I have, too.

Oswald. Well, you may take their word for it. They know what they are talking about! Oh! that that great, free, glorious life out there should be defiled in such a way!

Pastor Manders is outraged, and when Oswald leaves, he delivers himself of a tirade against Mrs. Alving for her "irresponsible proclivities to shirk her duty."

Manders. It is only the spirit of rebellion that craves for happiness in this life. What right have we human beings to happiness? No, we have to do our duty! And your duty was to hold firmly to the man you had once chosen and to whom you were bound by a holy tie.... It was your duty to bear with humility the cross which a Higher Power had, for your own good, laid upon you. But instead of that you rebelliously cast away the cross.... I was but a poor instrument in a Higher Hand. And what a blessing has it not been to you all the days of your life, that I got you to resume the yoke of duty and obedience!

The price Mrs. Alving had to pay for her yoke, her duty and obedience, staggers even Dr. Manders, when she reveals to him the martyrdom she had endured those long years.

Mrs. Alving. You have now spoken out, Pastor Manders; and to-morrow you are to speak publicly in memory of my husband. I shall not speak to-morrow. But now I will speak out a little to you, as you have spoken to me.... I want you to know that after nineteen years of marriage my husband remained as dissolute in his desires as he was when you married us. After Oswald's birth, I thought Alving seemed to be a little better. But it did not last long. And then I had to struggle twice as hard, fighting for life or death, so that nobody should know what sort of a man my child's father was. I had my little son to bear it for. But when the last insult was added; when my own servant-maid—— Then I swore to myself: This shall come to an end. And so I took the upper hand in the house—the whole control over him and over everything else. For now I had a weapon against him, you see; he dared not oppose me. It was then that Oswald was sent from home. He was in his seventh year, and was beginning to observe and ask questions, as children do. That I could not bear. I thought the child must get poisoned by merely breathing the air in this polluted home. That was why I placed him out. And now you can see, too, why he was never allowed to set foot inside his home so long as his father lived. No one knows what it has cost me.... From the day after to-morrow it shall be for me as though he who is dead had never lived in this house. No one shall be here but my boy and his mother. (From within the dining-room comes the noise of a chair overturned, and at the same moment is heard:)

Regina (sharply, but whispering). Oswald! take care! are you mad? let me go!

Mrs. Alving (starts in terror). Ah! (She stares wildly toward the half-opened door. Oswald is heard coughing and humming inside.)

Manders (excited). What in the world is the matter? What is it, Mrs. Alving?

Mrs. Alving (hoarsely). Ghosts! The couple from the conservatory has risen again!

Ghosts, indeed! Mrs. Alving sees this but too clearly when she discovers that though she did not want Oswald to inherit a single penny from the purchase money Captain Alving had paid for her, all her sacrifice did not save Oswald from the poisoned heritage of his father. She learns soon enough that her beloved boy had inherited a terrible disease from his father, as a result of which he will never again be able to work. She also finds out that, for all her freedom, she has remained in the clutches of Ghosts, and that she has fostered in Oswald's mind an ideal of his father, the more terrible because of her own loathing for the man. Too late she realizes her fatal mistake:

Mrs. Alving. I ought never to have concealed the facts of Alving's life. But ... in my superstitious awe for Duty and Decency I lied to my boy, year after year. Oh! what a coward, what a coward I have been!... Ghosts! When I heard Regina and Oswald in there, it was as though I saw the Ghosts before me. But I almost think we are all of us Ghosts, Pastor Manders. It is not only what we have inherited from our father and mother that "walks" in us. It is all sorts of dead ideas, and lifeless old beliefs, and so forth. They have no vitality, but they cling to us all the same, and we can't get rid of them.... There must be Ghosts all the country over, as thick as the sand of the sea. And then we are, one and all, so pitifully afraid of the light.... When you forced me under the yoke you called Duty and Obligation; when you praised as right and proper what my whole soul rebelled against, as something loathsome. It was then that I began to look into the seams of your doctrine. I only wished to pick at a single knot; but when I had got that undone, the whole thing ravelled out. And then I understood that it was all machine-sewn.... It was a crime against us both.