Being without an adequate stooge against whom to play—barring one scene at the beginning of the film with a debuting Thora Hird—Hay is not quite at his best here, in this ridiculously plotted wartime comedy, but still proves good value for money, though the oft great John Mills, given something of a thankless task, never appears in any way comfortable with his role. However, the sharp screenplay’s gag-heavy dialogue is often excellent, with the picture proving generally well-crafted. In it, Hay plays Professor Davis—the vaguely seedy, decidedly incompetent principal of a financially failing correspondence school—who heads to the Ministry of International Commerce, Whitehall, to seek remuneration from his one and only pupil (Mills), a young civil servant who quite rightly gives him short shrift. However, confused by the vague promise of a job offer, the old fraud disastrously comes to be mistaken for the eminent visiting economist Professor Davys, who is due at the ministry to advise on a soon-to-be-signed South American pact. Never the less, his bungling somehow comes to expose a Nazi plot to hijack said treaty, which he and his former pupil unaccountably set about quelling by themselves.