Robin's Winter Song

On a beautiful autumn day, as Robin sings from his branch, he notices the leaves swirling in the wind. Something is different - but what is it?

And it isn't just the leaves - the squirrels are scurrying, the mice are scampering and the finches are flying south. Even Bear is looking for a warm cave to sleep in. And they all say it's because Winter is coming. But who is Winter and why has Robin never met him before?