A bachelor becomes the unwilling guardian of his autistic, intellectually disabled sister; then an experimental treatment works a dramatic change in her brain and his attitude.

Autistic since birth, 28-year-old Molly McKay is a carefree young woman with an incredible zest for life. Her brother Buck McKay, a 32-year-old bachelor with a full social calendar and a booming career, has had little contact with Molly over the years until the institution that cares for her closes down. Now it's up to Buck to take his sister in...and that's turning into a full-time job. Daring, childlike and very energetic, Molly completely envelops her brother's life and turns his ordered world into chaos. Then just when Buck becomes desperate, Molly becomes a candidate for a new medical procedure that could cure her completely...but is it worth the risk? Molly sure thinks so...she's ready to experience everything.—MGM/UA Home Video