midnight
Because I saw that it was addressed to you two . Colonel Welsh taught me that secret code of his just before he sent me down to this place . I have n't been lucky enough , yet , to have had the chance to use it . '' Since their messenger-boy mission had been washed out , at least until Colonel Welsh 's arrival at midnight , there was no reason to check Major Parker 's connection with Intelligence , but Dave somehow could n't pass it by . `` I see , sir , '' he said quietly . `` Well , Farmer and I were taught something , too , before we left . We were taught to take an interest in copper discs .