half past nine
His last words were that everything was thoroughly satisfactory , and that he had learned all he wanted to know . Which , as was proved that same night , was the simple truth . I owed it to my colleague Glossop that I was in the centre of the surprising things that occurred that night . By sheer weight of boredom , Glossop drove me from the house , so that it came about that , at half past nine , the time at which the affair began , I was patrolling the gravel in front of the porch . It was the practice of the staff of Sanstead House School to assemble after dinner in Mr Abney 's study for coffee . The room was called the study , but it was really more of a master 's common room . Mr Abney had a smaller sanctum of his own , reserved exclusively for himself .