Expect to hear: Relaxing and melancholy ambience, building into clean guitar passages which don't feel like forced "post-rock" build-ups like everyone else started doing. Gruff and hoarse spoken word passages. Crushing sludge/doom metal riffs that plod along with earth-shaking force (file under: 2nd heaviest thing in the world). Harp (???!). More devastatingly heavy riffs. etc. etc. etc.
Honestly, anything I write about this masterpeice is going to be completely inadequate, so you should probably just hear it and let the music tell the story itself (But be patient!). The composition and the atmosphere it creates is profound, and incredibly moving.