seven o'clock
`` You old dear , '' she said , `` you 're so proud of your beloved ` Argus . ' I believe you worry over every word that goes into it . '' `` And over every s that is upside-down and is n't detected by my eagle eye , '' laughed Dorothy , locking the door and carefully hiding the key in the place where half the college knew it was kept . It was seven o'clock -- no use going home to dinner . Dorothy decided to get an early start with Ward 's `` Poets , '' and to dine later in the evening on ship 's biscuit and a glass of milk . The library was very quiet . She read busily , concentrating her attention upon the pages before her , oblivious of her surroundings , forgetful even of the mysterious letter and the theory , which , despite her declaration to Beatrice Egerton , she had formed concerning it .