Nanko is the man who brings the news that the ship that has landed on the island is not the Aleuts'. Rather, the ship has arrived to carry the people of Ghalas-at to the mainland (woo!). His role in the novel is that of a messenger. He's also, we should add, a figure of miscommunication. It's Nanko who tells Karana that her brother is already on the ship – which, of course, turns out not to be true at all. On a side note, Ulape is in love with Nanko.