Gustaw Tabor is a wealthy European businessman who lives in Paris, France. He is related to the New York architect Karel Tabor.
Gustaw doesn't have children of his own, so he started looking for an heir among his relatives. He hired private investigator Elmo Yancey to do a character-check on Karel Tabor and his son, John, to see if the later was "worthy" of an inheritance.
Gustaw is a widower, and has had problem's from his late wife's brother, Paul Clermont, who feels himself the rightful heir.