I found this to be one of the cleverer "Carry On" films with Kenneth Williams on good form as the revolutionary "Citizen Camembert" aided by his sidekick "Bidet" (Peter Butterworth) making sure that all the nasty aristos turn up for their appointment with madame guillotine. The fly in their ointment soon becomes the enigmatic and chivalrous Brit "Sir Rodney Ffing" (Sid James) and his aide-de-camp "Pue" (Jim Dale) who are bent on frustrating their French nemeses and rescuing the "Duc de Pommfrit" (Charles Hawtrey) before trying their best to ensure that the famous vertical chopper gets two, more appropriate, victims. Instead of the "Scarlet Pimpernel" we have the "Black Fingernail" but otherwise, it's a fairly enjoyable parody of the Orczy story with some good one-liners, a nice dynamic between James and Butterworth and, mercifully, little of the annoying Dale to clutter up the proceedings. It looks good, the jokes are frequently quite pithy and for my money this is James at his best. Good fun.