Eben Alexander, a Harvard neurosurgeon who was in a coma for seven days in 2008, encounters an “angelic being” who guides him into the “deepest realms of super-physical existence.” His “Proof of Heaven: A Neurosurgeon’s Journey Into the Afterlife,” published last fall, peaked at No. 4 in December and is now No. 10. RNS photo courtesy Amazon.com. *Note: This image is not available to download.