On land in Hong Kong's lush northern suburbs near the border with the Chinese mainland, farmer Chan Koon-wing is working to keep a legendary scent alive in the city known as the Fragrant Harbor.

Chan runs Hong Kong's last commercial plantation of agarwood trees, prized through the centuries for aromatic resin used to make incense, perfume and medicine.

He has no hope his sons will carry on the labor-intensive business and also faces an increasing threat from thieves. But the tree's rich history that intersects with the lives of his forefathers gives Chan a sense of mission. And the trade in the wood and oil is lucrative.