About
midnight
As far as elucidation went Marley naturally looked to Steel . `` I should like to have your explanation , sir , '' he said , gravely . `` Positively , I have no explanation to offer , '' David replied . `` About midnight I let myself out to go for a stroll , carefully closing the door behind me . Naturally , the door was on the latch . When I came back an hour or so later , to my horror and surprise I found those marks of a struggle yonder and that poor fellow lying on the floor of the conservatory . '' '' ` Um .