As the play begins, Marc addresses the audience and explains that his good friend Serge—a successful dermatologist whom Marc has known for over fifteen years—has recently bought a painting. The painting is four feet by five feet, and it is entirely white save for a few faint diagonal lines running through it. Serge has been lusting after the painting for months, and Marc is going over to Serge’s flat to take a look at it. At Serge’s, the two men examine the painting and each separately feel a series of “wordless emotions.” When Marc asks Serge if the painting was expensive, Serge reveals that it cost him two hundred thousand francs, though he tells Marc that he actually got it for a bargain—it was done by a famous painter named Antrios. When Serge asks Marc what he thinks of the painting, Marc tells him he thinks it is “shit.” Serge addresses the audience directly to explain that Marc is an intellectual and an “enemy of modernism” who simply cannot understand the painting. Serge becomes angry with Marc, and urges him to explain exactly why he thinks the painting is shit. Marc cannot back his feelings up, but steps forward to address the audience, revealing that he is deeply unsettled by the “ridiculous” painting. To calm his nerves, he plans to go visit their friend Yvan, and discuss the painting with him.
At Yvan’s, Marc comes across his friend down on all fours, searching for the cap to one of his special felt-tip pens. Marc and Yvan discuss Yvan’s impending wedding to his fiancé Catherine, and then Marc begins telling Yvan about Serge’s new purchase. Marc rails against how ridiculous the painting is, while Yvan asks how much it cost and who the painter is. Yvan has never heard of Antrios, and is astounded and concerned to hear that the painting cost two hundred thousand francs. Yvan ultimately decides, however, that as long as the painting makes Serge happy and isn’t hurting anyone, it’s fine for him to have bought it. Marc insists that the painting is hurting him personally. Moreover, he’s upset that Serge seems to have lost his sense of humor about himself—and about art—entirely. Yvan assures Marc that he will go over to Serge’s apartment, see the painting for himself, and get Serge to laugh.
At Serge’s flat, Serge and Yvan sit in the common room—which is now devoid of the Antrios—discussing the upcoming wedding. Serge and asks Yvan if he has seen Marc recently; Yvan lies and says he has not. Serge admits that he saw Marc the other day—Marc left upset, though, by Serge’s newest purchase. He asks if Yvan wants to see the piece of art that has “ruined” him, and goes to fetch the Antrios. As Yvan considers the painting, he begins to really like it. Both men discuss the “magnetic” pull the painting has. Serge reveals the price to Yvan, and after a moment of silence, both burst out laughing. Serge confides that Marc hated the painting, and responded humorlessly to it. Serge, however, doesn’t blame Marc for overreacting to the painting—he believes Marc doesn’t understand modern art at all, and asks Yvan to agree with him on his belief that their beloved Marc has begun to “atrophy.” Yvan remains silent.
At Marc’s apartment, Yvan fills Marc in on his recent visit to Serge’s. Yvan tells Marc that the two of them laughed over the painting, and Marc is shocked. Yvan reveals that he actually liked the Antrios, and that it inspired feelings in him; he argues that there is a “system” at work behind the piece. Marc derides Yvan and laughs at him, accusing him of “parroting Serge’s nonsense.” Yvan warns Marc that he notices Marc has become bitter over the years. Marc leadingly asks Yvan to describe the feelings he felt looking at the painting, and whether it made him happy. Yvan addresses the audience, revealing that though the painting didn’t make him happy, he’s not a very happy person to begin with. Marc then steps forward and in his own monologue wonders why he is so bothered by Serge’s obsession with modern art, and then vows to stop attacking Serge over the Antrios. He promises himself that he will be on his best behavior with his two friends the next time he sees them.
Marc and Serge are alone in Serge’s apartment, and Serge tells Marc that Yvan liked the Antrios. Marc asks to take another look at the piece, and Serge fetches it from the other room. The two men stare at the painting, and neither says anything. Serge suggests they not let themselves get “bogged down” by their feelings about the piece. Changing the subject, Serge suggests Marc alleviate some stress in his life by reading a book by Seneca, the Roman philosopher. He describes it as a “masterpiece” and an “incredibly modern” text. Marc circles back to the painting, though, revealing that he has been thinking a lot about Serge’s purchase, but has decided to be happy for him. He apologizes for his initial overreaction to the painting, and notes that he has been tightly wound. Serge again urges Marc to read Seneca. Marc is annoyed by this, and says so. Serge apologizes for being obnoxious and superior.
Marc asks Serge where he is going to hang the painting, and whether he’ll frame it; Serge replies that it would be ridiculous to frame the painting, as the artist would not want the canvas interrupted. Marc teases Serge for responding to his question so pretentiously, but to avoid arguing, changes the subject and asks what movie they’ll go to see once Yvan arrives—Yvan is running close to half an hour late. Serge expresses his extreme upset at Yvan’s lateness, but Marc accuses Serge of taking out his own suppressed frustrations with Marc on the poor Yvan. Serge, now addressing the audience, admits that he is frustrated with Marc, and wonders why the Antrios has put such a strain on their friendship. Marc steps forward into a monologue and expresses similar concerns. He thinks that the Antrios is just the latest development in a long history of small grievances between the two friends, and is both angry and afraid that Serge has come to value art and modernist ideals over friendship.
The doorbell rings and Yvan blusters in, in crisis mode. There is a stressful development in the wedding planning—Yvan and Catherine are fighting as they struggle to figure out whose names to include on the invitation. Yvan’s mother is now involved in the fight, and he feels pressure on all sides to please all the women in his life. Marc snidely suggests that Yvan, to relieve his stress, read the book by Seneca. Serge and Marc begin arguing about the book, but Yvan insists that after his day he cannot handle any more fighting. He suggests they all head out for dinner. Marc and Serge argue about this, too, unable to decide on a restaurant. Yvan threatens to go home if the fighting continues. Marc and Serge then descend upon Yvan, telling him that if things are so stressful he should just cancel the wedding entirely rather than allow himself to be bossed around by Catherine. Yvan attempts to change the subject by bringing up the Antrios, telling Serge that he was thinking of him the other day when, at his stationery company job, they had to print several posters by an artist who paints white flowers on white backgrounds. Serge, offended, retorts that the Antrios is not white. The three begin to fight about the painting—when Yvan attempts to backtrack and state that he loves the Antrios, Marc becomes upset and even offended. Yvan again threatens to leave, but the petty fighting only gets worse. Yvan, unable to take anymore, walks out the door. Marc offers to leave as well. Serge chastises Marc for having upset the sensitive Yvan, and Marc, in a moment of true reflection, wonders what any of the three of them even have in common anymore.
The doorbell rings, and Yvan blusters back in. He says that he realized on the way downstairs that Marc, due to his “insane aggression,” was deeply in need of help. Yvan reveals that the other day, during a session with his therapist, he discussed Marc and Serge’s relationship, and his therapist gave him the answer to their problems. Marc and Serge are upset that Yvan would have brought them up in therapy, but agree to hear what the therapist said nonetheless. Yvan produces a piece of paper from his jacket pocket, and when the other two tease him for making notes, he assures them that the material is complex. The note is slightly confusing, but essentially posits that if two people depend on each other too heavily and build their lives and personalities around one another, the friendship will fail.
Serge tells Marc and Yvan that he is exhausted from fighting. Yvan agrees and suggests they all go to dinner, but Serge insists Marc and Yvan go alone. Yvan begs the two to stop fighting, but Serge accuses Yvan of being self-righteous. Serge, seized by a sudden impulse, removes the Antrios from the room. Marc teases Serge, but Serge asks Marc if he has considered that he and Yvan have a genuine attachment to the painting, and whether he knows that his words are actually hurtful. Serge tells Marc that, for instance, when Marc began dating his current girlfriend Paula, Serge saw how much Marc loved her and spared Marc from his own opinion that Paula was “repellent.” Marc and Serge begin physically fighting one another, and Yvan intervenes, but one of the other two strikes him in the ear. Serge fetches Yvan a compress, and while Yvan nurses his injured ear, he laments how violent and cruel his two friends have become. Serge and Marc begin arguing about the painting again, and it is revealed that the crux of the issue between them is that Marc sees Serge’s purchase of the Antrios as an act not only of independence from Marc and his opinions, but defiance of them, causing Marc to feel abandoned and betrayed.
As Marc and Serge speak frankly and calmly for the first time all evening, Yvan applauds the fact that his therapist was right, and it is Yvan who has finally mediated the other two’s argument. Marc chastises Yvan for holding himself apart from the other two, reminding him that he is just as culpable in all this as any of them. Yvan becomes frustrated, and asks why the three of them even see each other anymore if they hate each other so much. Yvan tells Marc and Serge that all he wants to be is their friend, even if he has to return to his role as the “joker” of the friendship. The men all share a moment of silence. Yvan asks if there is anything to eat—he is starving. The three men silently share a bowl of olives. Yvan laments the dissolution of their friendship over a tiny white square. Serge leaves the room and fetches the Antrios. He returns with it, and asks Yvan if he can borrow one of his felt-tipped pens. Yvan hands the pen to Serge, who then tosses it to Marc and urges him to deface the Antrios. Yvan begs Marc not to, but Marc leans toward the painting and draws a tiny skier in a woolly hat sliding down a slope. After a long silence, Serge suggests they all go out to eat.
Yvan addresses the audience while, in the background, Marc and Serge use cleaning supplies to remove the skier from the Antrios. Yvan reveals that at dinner that night, Marc and Serge suggested they enter a “trial period” of reconciliation, and the phrase moved Yvan to tears. In the days since the dinner, Yvan has found himself crying uncontrollably and nearly constantly.
Serge moves away from the cleanup, dries his hand, and steps forward. He reveals that once he and Marc had finished cleaning the painting and restored it to its pristine white, he asked Marc if Marc had known that felt tip pens were washable before he drew on the Antrios. Marc said he hadn’t, and Serge said he hadn’t either. In reality, though, Serge had known, and so his gesture to Marc is revealed to have been a hollow one. Serge cannot tell Marc that he knew the ink would wash off, but also feels guilty beginning their “trial period” with a lie.
Marc steps forward and begins to describe the Antrios. Under white clouds, white snow is falling on a white mountain. A skier glides downhill before disappearing back into the landscape. The painting, Marc says, represents a man who moves across a space and then disappears.