As a dissertation on how to do nothing well, film anent Britain’s naval blockade earns a niche all its own. Producers have lavished their brainchild with a wealth of detail that takes care of all except one thing – imagination.This yarn of the economic war staged by the navy through its control of shipping veers from the sea to take a jaunt on espionage in London. Conrad Veidt as the Danish seaman is authentic to the point where it’s questionable as to his ease as a lover in the smart company of Valerie Hobson. Her role is handled with aplomb. All of the rest reach for the same standard, particular attention going to Hay Petrie for his comedy work in a dual role.