In Heart of Darkness, by Joseph Conrad, Marlow travels through Africa to meet Kurtz--this mysterious figure at the end of his journey. Once he finds Kurtz, the man is a shadow of his former self, twisted and destroyed by the jungle that surrounds him. In Heart of Darkness, Kurtz loses his humanity in the jungle and eventually dies. Marlow is luckier and is able to return to civilization with his sanity, humanity, and the realization of how quickly a man can lose himself if we aren't careful.
In Silence, by Shusaku Endo, Rodrigues travels through Japan looking for Ferreira--a mysterious figure at the end of his journey. Once he finds Ferreira, the man is a shadow of his former self, changed and destroyed by the Japanese that surround him. In Silence, Ferreira loses his faith in Japan and eventually apostatizes. Rodrigues is luckier and is able to retain his faith, although he does "apostatize" by trampling on the fumie. Rodrigues realizes how quickly a man can lose his faith when placed under severe trials.
I see a lot of similarities. Dang you, Endo! Not cool!