The Phoenix Song (гет)

AU After the events of her first year, Ginny is determined to be ready for Tom's eventual return. Elsewhere, Harry has been rescued from his Muggle relatives by a godfather he never knew. When horrific events bring these two together, they learn they are part of a prophecy to end Tom Riddle once and for all. But what is the power he knows not, and why can they both hear the song of the phoenix?