When a reporter is killed under mysterious circumstances, the political cartoonist on his paper begins to investigate on his own. He finds that a vengeful industrialist may be trying to manipulate an international peace conference to stage a bombing attack on London.
Briant Gaunt

Mary Stevens

Minister Peters of Grovnia

Socks, American Henchman

Smith, Bowler-hat Henchman
Pierre, Knife-throwing Henchman
Tony, Slender Henchman

Mac, Newspaper Editor
Sir George, Lead Conspirator
Baron von Kleisch, Delegate
Harris

Dr. Marsh
Conference President
Secret Agent Fearns
Vronsky, Peters' Aide
Banks
Graham Stevens
Zadek
Groves