From Super Detective Picture Library #171, April 4, 1960.
A Polish scientist named Jacobwicz had been held at a facility at Peenemunde working on a project he refuses to disclose. He even kills the head of the unit controlling him rather than reveal his invention. When bombers destroy the plant and he is freed, he still refuses to say anything to the Resistance who find him. John Steel is sent to learn what he can about whatever it was the Pole had invented.