On the eve of their high-school graduation, two academic superstars and best friends realize they should have worked less and played more. Determined not to fall short of their peers, the girls try to cram four years of fun into one night.

Harriet finds art imitating life when she discovers certain songs can transport her back in time – literally. While she relives the past through romantic memories of her former boyfriend, her time travelling collides with a burgeoning new love interest in the present. As she takes her journey through the hypnotic connection between music and memory, she wonders – even if she could change the past, should she?