A lyrical historical fantasy adventure, set in 1932 Spain and Germany, that brings to life the world of the novellas collected in ‚  Los Nefilim: Spanish Nephilim battling daimons in a supernatural war to save humankind.

Born of daimon and angel, Diago Alvarez is a being unlike all others. The embodiment of dark and light, he has witnessed the good and the horror of this world and those beyond. In the supernatural war between angels and daimons that will determine humankind's future, Diago has chosen Los Nefilim, the sons and daughters of angels who possess the power to harness music and light.

As the forces of evil gather, Diago must locate the Key, the special chord that will unite the nefilim's voices, giving them the power to avert the coming civil war between the Republicans and Franco's Nationalists. Finding the Key will save Spain from plunging into darkness.

And for Diago, it will resurrect the anguish caused by a tragedy he experienced in a past life.

But someone "or something "is determined to stop Diago in his quest and will use his history to destroy him and the nefilim. Hearing his stolen Stradivarius played through the night, Diago is tormented by nightmares about his past life. Each incarnation strengthens the ties shared by the nefilim, whether those bonds are of love or hate . . . or even betrayal.

To retrieve the violin, Diago must journey into enemy territory . . . and face an old nemesis and a fallen angel bent on revenge.