twelve o’clock at night
` What is the secret of it ? ' he thought , with a sidelong look at her haughtily-lifted head . He had not long to wait for the solution of the enigma . As he was returning at twelve o'clock at night to his room , along a dark corridor , some one suddenly thrust a note into his hand . He looked round ; a girl was hurrying away in the distance , Natalya 's maid , he fancied . He went into his room , dismissed the servant , tore open the letter , and read the following lines in Natalya 's handwriting : -- ` Come to-morrow at seven o'clock in the morning , not later , to Avduhin pond , beyond the oak copse . Any other time will be impossible .