The most "useful paper" in the series' lore is an written by the protagonist's mother, Manuela Valenzuela , decades ago in Mexico.
: Jess breaks her father out of a Mexican prison, and they go on the run to recover his hidden research. Il.Mistero.Dei.Templari.La.Serie.01x08.Albero.G...
: This paper contains the research that allowed Liam Sadusky's father to track the Pan-American treasure. The most "useful paper" in the series' lore