midnight
`` I guess that 's the trouble , '' Tom began ; `` my head aches -- '' `` Can you swim now ? '' Archer demanded . `` You go , '' said Tom ; `` my knee 's too stiff . '' `` If you everr say a thing like that to me again , '' said Archer , his eyes snapping and his freckled face flushing scarlet , `` I 'll -- '' `` I did n't think we 'd start till midnight , '' Tom said , `` and I thought my knee 'd be well enough by that time . '' The little boat , as they could see from the doorway , bobbed nearer and nearer and Archer could see that it contained two men . `` They 've got on uniforms , '' Archer said , `` but I ca n't see what they arre . Let 's keep inside . ''