Thanatonaunts. Empire of Angels (set of 2 books)

The legendary duology by Bernard Werber. The set includes 2 books: «Thanatonauts» and «Empire of Angels».
«Thanatonauts »
Death. A point of no return that makes the living feel confusion and fear. No one has returned from there, and there, beyond life,... no one has ever been as a guest. However, with the invention of thanatonautics, everything changes. A few daring individuals invented a way to travel along the edge of shadows, which has led to unpredictable consequences — for every faith wishes to prove its correctness and colonize the afterlife.
«Empire of Angels»
What is up there? Do all souls go to heaven? Can humanity be saved?
The pioneers of «afterlife geographical discoveries» Michel Penson and Raul Razorbak meet again to continue the epic of the thanatonauts. They are to practically learn all the subtleties of the angelic craft and understand the misty heavenly hierarchy. But they would not be true explorers if they stopped there. Where do angels go after fulfilling their purpose? Who makes decisions above the angelic world? And what if the answers to these questions are hidden in other galaxies?