midnight
`` I found it on the floor in front of the safe this morning . '' `` It is mine , sir . I must have dropped it last night . I worked extra until after midnight , sir , '' explained Jack , `` and on the way out I chased a mouse in here from the stairway , and when it ran under the safe I dropped to my knees to find it . The book must have fallen from my pocket . `` But what is wrong , sir ? '' `` The cash-box is not in the safe this morning . ''