In 1880, 10-year-old Winnie Foster, trapped by the rules imposed by her strait-laced family, runs away and discovers the humble Tucks who had accidentally stumbled upon a spring long ago that gave them eternal life. Winnie promises to keep their dangerous secret but then a sinister stranger arrives at their door with intentions to steal the immortal water for himself. Ultimately Winnie must choose whether or not to drink the immortal water and join them in an everlasting adventure – or live on in a natural way, living a life full of the ordinary beauty of growth and change.