then he walked bod around the graveyard , placing the boy 's small fingers on the newest and clearest of the headstones and the plaques , and taught bod how to find the letters of the alphabet when they appeared , beginning with the sharp steeple of the capital a. silas gave bod a quest-to find each of the twenty-six letters in the graveyard-and bod finished it , proudly , with the discovery of ezekiel ulmsley 's stone , built into the side of the wall in the old chapel .