The house is quiet, save for the soft moans echoing from the siblings' shared room. The brother, engrossed in his sister's story, feels his groin stir as she describes her fictional lover's touch. His hand wander, finding her thigh, then her panties, and finally her wet, eager slit. She gasps, her story faltering, but he silences her with a kiss, their tongues dancing as they explore each other's bodies, their familial bond deepening into something darker, something taboo.