Careful is set in Tolzbad, a fictional mountain town that exists under the constant threat of devastating avalanches. These avalanches can be triggered by a loud noise or even by a too-intense expression of emotion, so the people live with a steady, almost ritual suppression of their feelings, always watching for signs of losing self-control. An opening lecture underscores the town’s anxious caution with familiar cautionary chants like “Think twice!” and “Don’t stand so close to the walnut tree!”
The community’s greatest ambition is to serve the reclusive Count Knotkers, and two brothers, Johann and Grigorss, train to be his loyal servants. They are beloved by their mother, Zenaida, though she harbors deep resentment toward their brother Franz, who has been exiled to the attic. The ghost of their dead, blind father appears to Franz to warn of looming doom, lamenting that Zenaida never loved him and instead seemed to burn with love for the Count—a love that could never be openly fulfilled because of the Count’s own mother.
Johann is betrothed to Klara, the daughter of Herr Trotta, while Grigorss harbors a hidden, unspoken affection for Klara. The story takes a darker turn as Johann, drawn by forbidden impulses, becomes disturbingly drawn to his own mother. He secretly spies on Zenaida through the walls of the chimney, and after forging a love potion, he acts out a grave transgression while she sleeps. The horror of what he has done pushes him toward self-destruction: he burns his lips with a hot coal, cuts off his fingers with garden shears, and then throws himself from the mountain.
Grigorss’s fury grows when Zenaida reveals that her passion for the Count Knotkers has been rekindled since her own mother’s death, explaining that her love for the Count has always overshadowed Franz in her heart. The revelation seems to sever their bond, as she discloses that her hatred for Franz stems from memories of his father. Grigorss, in a bid to defend his father’s honor, challenges the Count to a duel, but Zenaida intervenes—she ultimately accepts Franz into the family.
Yet Klara drives Grigorss toward the duel. She carries a troubling, incestuous fixation with her father, Herr Trotta, who largely ignores her but showers attention on her sister Sigleinde. Her view of the chained wild mountain girl Gerda further fuels Klara’s scheme for revenge, and the duel becomes the first step in a larger plot. They duel with daggers, and Grigorss kills Count Knotkers. He staggers home, where Zenaida tends to him after his collapse, only to discover that he has slain her beloved master. In a crushing reversal, she expels him from the house and hanges herself in the attic, right before Franz’s eyes.
Grigorss is then taken by Klara to a mountain cave she once prepared as a private retreat for love, now repurposed for their plan. Klara reveals that she believes her father raped her and that they must arrange his death. Grigorss accompanies Herr Trotta on a sleigh ride, and a pistol shot triggers an avalanche intended to bury Trotta. The plan largely succeeds—except that Klara, in a final, tragic gesture, leaps into the sleigh to die while kissing her father.
Left alone in the secluded cave, Grigorss endures a grim solitude. A single teardrop triggers another avalanche, sealing his fate as he freezes to death, haunted by a vision of a joyful reunion with his parents. In the end, Franz and Sigleinde join the search for their vanished relatives, only to remain oblivious that those they seek are already dead.
