During 1941, in the Mediterranean, the Italians start using underwater chariots to mine the undersides of allied ships. Explosives expert Lionel Crabbe arrives in Gibralter to organise defences, but finds only two British divers available to help him. Worryingly, it appears that the Italians might be secretly using neutral Spain across the bay as their key base.
The Silent Enemy is a Film programme that first aired in 1958 and has been classified a U certificate.
