The Secret Service - May-Day, May-Day!

Unwin and Harding are assigned to protect the King of Muldovia, who is in London to sign an oil rights treaty. The Muldovian Prince wants the throne for himself, but his attempt to have the King assassinated is foiled when his hitman is startled by the miniaturised Matthew and falls to his death from an open window. The Prince then hides a bomb inside a toy bear intended for the King's son.