The Boys From Brazil

by Ira Levin (1976):

Is it a prank,

Jewish Nazi hunter Yakov

Liebermann wonders when he receives a phone call from an investigative journalist in Brazil with information on concentration camp doctor Josef Mengele who performed horrific experiments on people during World War II.

The journalist claims that Mengele, the “Angel of Death” of Auschwitz, is very much alive and hiding out in South America, and is planning to kill 94 men over several years. He is gathering a group of former colleagues for this project and the targets will all be 65 years old at the time of their murders. But before the phone conversation is over, the journalist is killed.