Name of book with floating skull

[miss1]

Im looking for a book. I read this many years ago and have no idea what the name is. There is a man on a journey somewhere and there is a skull that is floating behind him. He comes across a lady in the woods who tries to entice him in but turns out to have a evil man attached to her back. He also visits a house where there is lots of doors with people stuck behind them. I think its a religious book of some sort although I could be wrong. Any help would be appreciated. Thanks