It's 1970, and Erin and Catherine play a tennis match. Catherine, the school's star player, and Erin, the new girl. They fight hard for every point, as if something more than tennis supremacy is at stake. And maybe it is. For Erin didn't just arrive from another town; she also came from another time. The present. And Catherine isn't only a star tennis player. She's also Erin's mom.