nine o'clock
returned Diggory , nodding his head in a sagacious manner ; `` I 'm rather inclined to think he came in on purpose . '' By the end of supper a fresh rumour spread which caused the affair to assume a still graver and more important aspect . Lucas had reported the whole thing to the head-master , and the latter had expressed his intention of inquiring into it on the following day . The truth of these tidings was proved beyond all possibility of doubt when , next morning at breakfast , an announcement was made that the school would assemble immediately after the boys left the hall , instead of gathering , as usual , at nine o'clock . Every one knew what this meant . The subject had been discussed for hours in most of the dormitories on the previous evening , and when Dr. Denson ascended his throne there was no necessity for him to strike the small hand-bell -- the usual signal for silence ; an expectant hush pervaded the whole of the big room , showing clearly the interest which every one felt in the business on hand . `` I need hardly say , '' began the doctor , in his clear , decisive manner , `` that my object in calling you together is to inquire into a disgraceful piece of disorder which took place in the reading-room last night .