When he is forced to vacate the office of his debt-ridden correspondence college, 'Professor' Will Davis goes to the Ministry of International Commerce at
Whitehall in order to confront his one-and-only student,
PR man Bobby Jessop. To get Davis off his back, Jessop proposes to get him a job at Whitehall. Jessop then leaves in order to fetch a Professor Davys at the railway station. The professor is a leading
economist who has returned from a long stay in
South America in order to advise the British government on a trade treaty with the South American nations, which could be crucial to Britain's war effort. The clueless Davis is mistaken for the expert and gets involved in a series of interviews, giving answers based on
gambling,
con jobs,
double entendres or just plain ignorance. These scenes are very funny and are made more so by the reactions of an increasingly incredulous Joss Ambler as government minister 'Sir John'. Jessop later returns with 'Professor Davys' and the confusion is sorted out, though it has left the
BBC interviewers in a state of mental collapse. Jessop then discovers that the man he brought with him is in fact Crabtree, a member of a group of
fifth columnists working for
Nazi Germany. Jessop promises Davis a job if he will help him track down the real Professor Davys, who is being held in a
safe house by Crabtree's associates. Assuming a number of disguises, Davis and Jessop set off to foil the plot before the treaty is compromised. ==Cast==