Colonialism
One of the themes in several of Grenville's books is colonialism, and chiefly the damage that it did. The colonial British are seen as an arrogant invader in this novel; after constructing a penal colony in the region they set about ridding themselves of the region's indigenous people. This is sometimes done by trying to wipe out their history and make Aboriginal Englanders out of them - hence the little girl with whom Daniel is friends having to learn English and stop speaking her own people's language - and it is sometimes done by trying to wipe out the indigenous people all together. The party that Rooke is supposed to lead, alongside silk, is intended to capture Aborigines with the intention of beheading them.
Rooke ultimately ends up living and working in Antigua, where he dedicates his life to freeing slaves. Slavery in the islands is another example of colonialism in that as soon as a country was colonized the indigenous people were enslaved and forced to work for the colonial settlers.
Unlikely Friendship
Daniel is a grown man, an astronomer with an excellent education. He is from Britain, a world away from Australia, but he somehow manages to make friends with a little Aborigine girl who has little English and has never even heard of London let alone been there. Yet somehow a special and genuine friendship develop between them. The author contends that this friendship is possible because both of the parties keeps an open mind to the other. They are prepared and eager to see each other for the similarities that they have, and not their differences, and this shows that any friendship is possible, even an unlikely one, if both parties come into the friendship with similar intentions.
