A is for Ascher, cudgeled in Andover. B is for Barnard, strangled in Bexhill. C is for Clarke, struck down in Churston. Beside each body is an A.B.C. Railway guide; before each murder Hercule Poirot is notified. In one of Christie’s most twisted tales, the meticulous Belgian sleuth must navigate the eerie maze of a serial killer’s mind. D is for Doncaster, where the next victim dies... E is for evidence, ingeniously analyzed.