of the darkening of valinor when manwe heard of the ways that melkor had taken , it seemed plain to him that he purposed to escape to his old strongholds in the north of middle-earth ; and orome and tulkas went with all speed northward , seeking to overtake him if they might , but they found no trace or rumour of him beyond the shores of the teleri , in the unpeopled wastes that drew near to the ice .