A hot and humid night... A summer day when her frustrated body begins to ache, craving a man's penis, and she falls into forbidden love. Married and living with her husband's parents, An is troubled by her husband's infidelity. Then, her brother-in-law, who left home 10 years ago and has not been heard from since, suddenly returns after losing his job. Unable to welcome his selfish brother-in-law, the atmosphere in the house becomes tense. Then, in desperation, he loses his mind when he sees An's voluptuous breasts peeking through her sweaty clothes and attacks her...