Agatha Christie ABC Murders

BBC Radio 4 full cast dramatisation starring John Moffatt as the great Belgian detective. Alice Ascher is murdered at Andover. Betty Barnard is strangled at Bexhill on Sea. Each time, an ABC railway guide is found by the dead bodies and, each time, Poirot is warned in advance by a letter from someone signed 'ABC'. But who is ABC And can Poirot find out in time to prevent the death of C