Temple of Zong? Never heard of.

Indochina, 1951. Tonkin and northern Annam have been liberated by the Vietminh. In the south, the French are fighting a vicious battle to keep the corrupt regime in
Saigon in power.

We meet Ruben in Nha Trang, an Annamese port town where he debarked from a French ocean liner in search of a monastery that a script said had to be somewhere in the mountains of Annam.
It was not the only reason for his quest: he had inherited a chest with unusual contents: a small skeleton.
Accompanying the chest was this manuscript - played into his hands by an old librarian - from a relative who had not survived the war. In it, he mentioned a monastery of the unknown order of Zong. A Chinese word, he would later find out, but the order seemed to be Japanese....
He engaged a boy in Nha Trang, who would be his guide. Not only that: the boy has a grandmother and a mother. Ruben blends into Annamese life, trekking through forests and mountains with Nguyen and later also with Yen, Nguyen’s mother. They travel by smuggling ships, old junks and rattling coasters from North to South and back again, through a war-torn country.