The Vanished Messengerby E. Phillips OppenheimCHAPTER IThere were very few people upon Platform Number Twenty-one ofLiverpool Street Station at a quarter to nine on the eveningof April 2 - possibly because the platform in question is one ofthe most remote and least used in the great terminus. Thestation-master, however, was there himself, with an inspector inattendance. A dark, thick-set man,