nine o'clock
`` Mr. Bennett was calling on me , when this note was brought in . We both thought we 'd better see you at once about it and he was kind enough to drive me here right away in his car . '' Craig took the letter and we both read , with amazement : `` Are you an enemy of society ? If not , order Craig Kennedy to leave the country by nine o'clock to-morrow morning . Otherwise , a pedestrian will drop dead outside his laboratory every hour until he leaves . '' The note was signed by the now familiar sinister hand , and had , added , a postscript , which read : `` As a token of his leaving , have him place a vase of flowers on his laboratory window to-day . '' `` What shall we do ? ''