City of The Lost God — Jean Van Hamme

This two-volume book includes Between Earth and Sun. City of the Lost God: Thorgal, Aaricia and Kriss of Valnor are finally approaching Mavaxatl, the city of the lost god. When Thorgal understands the real goal of their mission and Kriss's duplicity, he tries to escape. But Kriss is determined that he complete the mission. Between Earth and Sun: Thorgal and Aaricia want to go home, but they won't go without their son Jolan. The Xinjin people have made a god of Jolan, and he doesn't want to renounce his power.