Mary Roach has already tackled sex and corpses, now she tackles the afterlife. Spook was actually pretty good in Roach's typical fun but scientific way.
Roach explores reincarnation, whether a soul exists (is it the big toe? or the sperm?), how much a soul weighs (surprisingly a lot of tests to determine this), ectoplasm, mediums, etc. She actually got to speak with Allison Du Bois, who is the basis of the TV series Medium.
I still don't believe quite a bit, and neither did Roach, but I do know that sometimes faith and belief is not based on fact or anything provable. It just is.