In the burned-out remains of a large house, Him, an acclaimed poet struggling with writer's block, places a crystal object on a pedestal in his study, and the building morphs into a beautiful home in an edenic landscape. Mother, the poet's wife and muse, awakens in her bed and wonders aloud where Him is. While renovating the house, she occasionally visualizes a beating heart within its walls.
One day, a stranger called Man turns up at the house, claiming to be an orthopedic surgeon and asking for a room. That night, Man suffers from dry heaves and Mother observes a wound on his side. Man's wife, Woman, arrives the next day. Mother is increasingly frustrated by her guests, but Him begs her to let them stay, revealing that Man is actually a fan whose dying wish was to meet Him. However, when Man and Woman accidentally shatter the crystal object, Him becomes angry and boards up his study. Man and Woman's two sons arrive unexpectedly and fight over Man's will. Oldest Son wounds his brother, and then flees after having his head smashed against glass by Him, leaving a bloody gash in Younger Brother's head.
Him, Man, and Woman take the injured son to the hospital. Mother cleans up and notices strange damage to the house, including a fly, a frog, and blood that will not stop dripping. She follows the blood to a tank of heating oil hidden behind the basement walls. Him informs Mother that Younger Brother has died.
Mother and Him are roused that night when dozens of people arrive unannounced at the house to mourn the dead son. The visitors behave in rude and presumptuous ways that irritate Mother, and she snaps and orders everyone to leave when they break a sink, partially flooding the house. She berates Him for allowing so many people inside and ignoring her needs, but their argument leads to passionate lovemaking. The next morning, Mother announces she is pregnant, which elates Him and inspires him to start writing again.
Some time later, Mother prepares for the child's arrival and reads Him's beautiful new poem. Upon publication, it is acclaimed and sells well. In celebration, Mother prepares a big dinner, but a group of fans interrupt. Mother tries to lock the doors, but droves of fans pour inside and begin to wreak havoc, damaging the house. Him is oblivious, but a disoriented Mother watches helplessly as military forces turn up to battle members of the cult that has sprung up around Him; his publicist organizes mass executions. Mother goes into labor and Him reopens his study so she can give birth inside.
The havoc outside subsides. Him finds that the fans have left gifts and are waiting. Him tells Mother that his fans want to see their newborn son. She asks why he won't make them leave, and he says he doesn't want them to. She refuses to hand over the boy to Him. Eventually, she falls asleep, and Him takes the child outside to the crowd. They pass the baby around wildly until he is inadvertently killed. Mother finds people eating her son's mutilated corpse. Furious, she attacks them. They turn on her and beat her savagely until Him intervenes. He begs Mother to forgive them, but she runs down to the basement oil tank and ignites the oil, causing an explosion that incinerates the crowd and destroys the house.
Him is unscathed by the inferno, but Mother is horrifically burned. She asks him what he is, and he replies, "I am I" and Mother was "home". He asks for her love, and, when she agrees, reaches into her chest and removes her heart, which he tears open to reveal a new crystal object. He places it on the pedestal and the house is transformed back into a beautiful home. A new Mother appears in the bed and awakens, wondering aloud where Him is.
