I have a theory about the bells! Now I'm sure anything is possible, previous comments and opinion about the bells could be right as well. But I was thinking more and more about it lately.
She uses the words 'Witchdoctor' and talks about 'Gravestones', it reminded me of Wicca and as someone said before it could be Wicca-inspired. Well a lot of Wicca and in Pagan Religious, Bells are believed to drive away evil spirits. Also the sound is thought to keep villages safe from storms and other natural calamities, bells also purify the air, and was caught me is they
cure illnesses, and cure them if potions were drunk from them. Sounds similar to "But the poison's running through you".
I don't know, just a thought. This song is so beautiful, it really is and I love it so much