The sun-drenched streets of Mexico City provide a stark contrast to the dark, lustful thoughts consuming two siblings. At 18 and 20, they're bound by blood and a shared secret - their mutual attraction. In the confines of their apartment, they engage in a silent, intense battle of wills. Her soft, untouched body aches for his touch, while he, wrestling with his conscience, hardens at the mere sight of her. The scent of their forbidden longing fills the room as they teeter on the edge of taboo.