The plot concerns what happens after an investigator finds a woman chloroformed in his apartment. When Markham returns to his apartment he finds a woman chloroformed but before he can summon aid, three gun-toting kidnapers appear from another room to announce that Markham's apartment will be used for a hideout until ransom is paid.

Markham becomes a target for an assassin when he is hired to impersonate mysterious international financier Max Bossman—whose enemies are numerous the world over— but Markham finds some pleasure in the assignment because he travels across Europe with Bossman's wife, Friday.