Mercury by Hope Larson utilizes mysteries as its main hook. The mystery of how a pendant ended up with the Fraser family, the mystery of Asa Curry and so on. The book, with its historical and modern settings in parallel to each other, goes from being a simple tale of teenage life, to a darker one with supernatural elements involved.
The resolution is not detailed but is sufficient to allow readers to come to conclusions with regards to the main plot, while leaving a few mysteries left to imagination. Mercury is an enjoyable book, with a nice twist to the ending. Going back and forth between the timelines kept me wondering how they are connected. The good characterization keeps the story from being boring, especially when the resolution is far away.