half past twelve
`` Sweeping his floor ! '' exclaimed Mr. Prohack , shocked , thunderstruck . `` I understood these were service flats . '' `` So they are -- in a way , but the housekeeper never gets up to this floor before half past twelve ; so it ca n't be the housekeeper . Besides , she 's gone out for me . '' `` Thank you , '' said Mr. Prohack , and remounted the staircase . His blood was up .