What is the author's style in Tooth & Nail: An Inspector Rebus Novel by Ian Rankin?

The language of the novel is English. The language is fairly simple and easy for most English speaking readers to understand. However, the novel is written by a man who lives in Scotland and his main character is also from Scotland, so the novel includes many phrases that are familiar slang in that part of the world, but might be unfamiliar to Americans or English speakers from other parts of the world.