Henry James is generally not known as a political novelist. But The Princess Casamassima (1886) is a riveting tale of terrorism, conspiracy, and the difficult choices that have to be made between conviction and morality, ethics and aesthetics. Witness a young man with a secret at the heart of his family past who becomes beguiled by people who do not have his best interests at heart, and experience the suspense of whether he will save himself in time. James captures the turbulence of a world riven by social and class conflict whose convulsions still reverberate today.
Using this edition: Henry James, The Princess Casamassima, intro. Derek Brewer,
https://www.penguinrandomhouse.com/books/261034/the-princess-casamassima-by-henry-james-edited-with-an-introduction-by-derek-brewer-notes-by-patricia-crick/