Amazon has added a new feature to its Kindle app on iOS that uses artificial intelligence to answers questions about the book you’re reading, the company has announced.

Available in the U.S. only, “Ask This Book” is described as an “expert reading assistant” that allows users to highlight any passage in what they are reading and ask questions about plot details, character relationships, and thematic elements. The feature’s answers are spoiler-free, revealing information only up to the current reading…