Eventually Eddie is taken out of his factory job and assigned to the mines, where he works 12-hour shifts in narrow tunnels where there is not enough room to stand up. One day, he is pistol-whipped by a guard for stepping out of line and complaining about another work crew, a group of Polish Christians, who have been stealing his crew’s wagons of coal. As a result of his repeated protests, the other crew is eventually transferred away, but Eddie suffers longtime effects (headaches, blurred vision) from the guard’s blow. Shortly afterward, the Nazis learn of his special abilities as a mechanic, and he is designated an “Economically Indispensable Jew,” a special status that, over the next year, saves him from the gas chambers three times. Eddie inwardly thanks his father, once again, for making sure that he learned a valuable trade in his teens.

Eddie becomes a mechanical engineer for IG Farben, the company that produces, among other things, Zyklon B, the deadly chemical used in the Nazis’ gas chambers. If a single pressure gauge on his watch malfunctions, he is told, he will die. To monitor the hundreds of gauges, he has an inspiration: He equips the 200 operators with whistles, fashioned by himself, with which they can alert him at the first sign of a breakdown.