From the Dead — Norah McClintock

Rennie is in Uruguay when his cousins discover a secret cache at their dead grandfather's cottage. Thousands of dollars in foreign currencies. A mystifying notebook. Multiple passports, some obviously fake. A gun. A disguise. And a photo of some Nazis. Rennie's mission: to find out whether there was more to the old man than anyone knew. Was he a spy? If he was, what did he do? And for whom? Did he help a Nazi war criminal escape justice? Rennie's quest leads him to Argentina and then to Detroit, where he finds more questions than answers and more than one gun pointed--and fired--in his direction.