Humans established a colony on a reasonably hospitable planet, and were doing well there, until another species, the Peshari, moved in and conquered them. The Peshari mostly let the humans run their own affairs, except that they keep ratcheting down the technology humans are allowed to have. A while back, their medical nanobots came off the permitted list, and one of the humans, Keller, has cancer.
He also has a plan.
Keller has been studying the Peshari, including reading all prior cultural research on them, and he has an idea. It's a clever idea, using a feature of their own culture and folklore, and the differences between that and human culture and folklore, against them.
This is a competently, professionally done story, and a good read. I recommend it on that basis. However, it's no more than competent and professional, and a Hugo winner needs to be more than just competent and professional.
Recommended as an enjoyable read, but not as a Hugo winner.