On May 23, 1918, Colonel Nathan B. Gregory (Edward Hearn)--an ace pilot and inventor known as the Eagle--was accidentally shot down by men from his own flying unit. Now, 14 years later, Gregory is taking revenge on these men, who have all become wealthy businessmen from the theft of his invention. Or is he? Stunt pilot Craig McCoy (John Wayne) doesn't know what to believe, but he is determined to protect the members of Gregory's traveling carnival and find the real killer.