Silvia is a ballerina completely consumed with dance. She locks herself in her apartment, determined to rehearse until she achieves perfection. Her compulsion makes her enter a state of growing delirium, to the point of not sleeping and hardly eating. Her rehearsals are only interrupted when she notices a dirt stain on the carpet. Silvia tries to clean it in vain. Tormented, she tears off the carpet trying to discover the origin of the stain but the stain relentlessly continues to grow and invades the apartment little by little.