Published in Jumbo Comics #70, Dec 1944 - 6 pages
Recovering from a wound in England, ZX-5 recounts to a doctor the tale of a German who helped him in a mission, receiving a medal from both the UK and US. Something suspicious is going on in a German hospital and ZX-5 must infiltrate to learn what. He discovers an operation that will allow pilots to fly at phenomenally high altitudes.