The Naked Diplomat(1963)

Félix, a somewhat clod-hopping young man, finds himself in the Grand Hotel of Little Lagonda, barefooted and in pyjamas. He is soon followed by a hooded, fat and leggy gangster. This is all the more strange as the hotel is under quarantine with the pretext of a plague-epidemic, in order to make it a suitable ground for the negotiations of certain oil-companies.