four o'clock
She put the copied note in an emblazoned envelope , and directed it to Edgar Caswall at Castra Regis . This she sent off by one of her grooms . The letter ran : `` DEAR MR. CASWALL , `` I want to have a chat with you on a subject in which I believe you are interested . Will you kindly call for me one day after lunch -- say at three or four o'clock , and we can walk a little way together . Only as far as Mercy Farm , where I want to see Lilla and Mimi Watford . We can take a cup of tea at the Farm . Do not bring your African servant with you , as I am afraid his face frightens the girls .