one o'clock
`` The _ concierge _ , monsieur , is my husband . He will be here for a certainty at one o'clock . '' `` Good , madame ! At one o'clock I shall return . '' He smiled , nodded , and ran down the first flight of stairs ; but by the window at the half-landing he stopped and looked back . `` Madame , tell me something ! What is the rent of the _ appartement _ ? ''