Started listening to some of the soundtrack from The Road. If you want something erie and sinister for the area we're in I'd suggest https://www.youtube.com/watch?v=oMnVp4p0ns4. I imagine this as starting to play when you get close enough to feel the sinking feeling/supernatural dread from the sacrifical area, you get to the harsher tones around 1:10 when you approach the inner sanctum and start being able to see parts of what is inside, with the music stopping around 1:25 when you see the altar and the scene itself. Haven't found something yet where the whole song maps to the situation, after 1:25 the song starts sounding more appropriate for panic and tense fear rather than slow, sinister dread.
EDIT: This might work, but again it also seems more fitting for an active danger rather than dread. https://www.youtube.com/watch?v=irx_QeW2EuY
EDIT: This might work, but again it also seems more fitting for an active danger rather than dread. https://www.youtube.com/watch?v=irx_QeW2EuY