Ark Royal Riddle

Published in Flying Aces, April 1940.
"A sleek 'Defiant' roaring westward over the wastes of the Atlantic! Aboard it, seeking an elusive moving dot on the trackless sea, were Dick Knight and Larry Doyle. Yet also aboard it was a mysterious envelope bearing an imposing red sea. How much depended upon that secret packet was something Knight didn't know. But Fate could have told him that much more was to depend on - a strangely muddled dinner engagement!"