When business magnate Robert Jeffreys announces his investment in airships, he hosts a promotional flight for a group of reporters. Working undercover in the crew is retired spy Augusta Peel. She'd rather be working on her book repair business but Inspector Fisher of Scotland Yard has persuaded her to help with a surveillance operation.
The press trip on the airship takes a turn when a body is found in a cabin. Augusta now has a new challenge on her hands. Can she identify the murderer? It's tricky to find a motive among the sophisticated passengers - some of them are sophisticated liars too.
Events escalate when a second death occurs. The airship murderer is covering their tracks. Augusta faces a race against time before the culprit tracks her down and silences her too.