sir did n't say anything for once , '' i was bounded with a promise , that i had done with your mother when she was on her last breath , that her son , will one day become a famous detective and will himself catch steel , so satyendra nath bose had just go on with his promise , '' the end the old man blinked his eyes for a little bit and then took a deep sigh , in order to bring out his grandson from his story .