midnight
He sailed his boat up to the town , and before landing , said to Tom : -- `` When I 'm ashore , you put off a little way from land and lie-to for an hour or so . When I want you , I 'll come down here to the water 's edge and whistle like a Whip-Will 's Widow . When you hear me , run ashore . If I do n't come by midnight , go back to camp , and march at once for Mobile . '' `` Why ca n't I lie here by the shore till you come . You 're going into danger and may need me . '' `` First , because there are ruffians around here who might put you ashore and steal the boat ; but secondly , because I do n't want to excite suspicion by having our boat seen around here at night .