Intro. Louise Campbell is a sixth-year student at Hogwarts, Slytherin, living at the height of the Second Wizarding War. When she realizes that the world is heading for destruction, she uses a time-turner and goes back to the past — to the time when James Potter, Lily Evans and Severus Snape were still students.
Their goal is to warn Dumbledore about Voldemort's Horcruxes. She succeeds, but is forced to remain at that time as a student. Caught between two eras, Louise attends classes alongside people who, in the future, would mark history.
Between secret meetings and conversations by the Black Lake, they live an intense and doomed romance. At the Yule Ball, Louise learns that Snape was with Voldemort that night. Heartbroken, she decides to return to the future after revealing to him the truth about who she really is.
Seriously injured upon returning, Louise wakes up days later in the infirmary. The world has changed: Voldemort is dead, the Order of the Phoenix has won... But the price was all she left behind.