When winter comes...
You'll hear no lions roar...
No stags grazing the fields...
No roses growing in the meadows...
No snakes in the sand...
The krakens will freeze where they swim...
The flayed men will rot and wither...
No trouts swimming in the river and no falcons flying in the air...
Not even the dragon's breath will warm you in your halls.
You shall hear only the wolves howl... 
And then you will know. Winter has come."