It's based on the Greek myth that basically revolves around Eurydice dying, and her husband, Orpheus, travelling to the Underworld and playing such sad and mournful music that he was allowed to take Eurydice back to the land of the living.
Read more on Wikipedia.
I've lost you my lovely
To the depths of an ocean
My blind faith,
I follow you with my hope and devotion
I'll sing for your freedom
I'm lost to release you
No heaven waits for us my sweet
I'll follow your demise to hell and beyond
Eurydice music video on YouTube
Sleepthief - Dawnseeker on: Last.fm, Discogs, Amazon.