noon
Indeed , the human element of jealousy , so often responsible for the frustration of the worthiest human ambitions , was not absent from the minds of the four now concerned with this problem . Each desired to solve it , and while no rivalry existed among them , save in the case of the two older men , it was certain that the eldest of the four would not lose his hold on his own theory , or be at very vital pains to stultify it . All , however , were fully conscious of the danger before them , and Frith , from the first , directed that none was to work alone , either in the Grey Room or elsewhere . At noon a telegram arrived for Mr. Frith from Scotland Yard . It recorded the fact that Peter Hardcastle was dead , and that examination had revealed no cause for his end . The news reached Sir Walter at once , and if ever he rejoiced in the death of a fellow-creature , it was upon this occasion . It meant unspeakable relief both for him and his daughter .