I'm a huge fan of Mark Lawrence, and Red Sister is my favorite of his books so far! It tells the story of Nona Reeve (eventually Nona Grey), a girl saved at the eleventh hour from execution. Nona is
taken to the Convent of Sweet Mercy, where girls are trained to be killers. That's right: warrior nuns, espionage nuns, poisoner nuns, and nuns who command elements of the supernatural. The story is set on a planet orbiting a dying sun, almost completely encrusted in ice save a narrow band between the ice walls where the remnants of humankind survive.
The book invites inevitable comparisons to the Kingkiller Chronicle or the Harry Potter series for its "school" setting, but Lawrence successfully puts his own mark on the familiar trope. The result is a book that's accessible to mature YA readers but wholly satisfying to an adult audience. There is so much I loved about this book: the characters, the setting, the hand-to-hand combat, the intrigue, mystery, betrayal, and surprising twists. The story comes to a satisfying resolution of the main arc, but leaves the reader eager for the next in the series. Oh, and the epilogue made my head spin.
Though nowhere near as grimdark as Lawrence's Broken Empire series, the book is dark in tone, with a few mature elements. There's some gritty violence, particularly graphic in the final showdown. There's also one scene of animal abuse (by a villain) which serves the story, but might be upsetting for some. If you fall into that category, go ahead and give this terrific book a chance, and when you see the scene coming (you'll know what's about to happen) just assume the worst and skip a few pages.
Red Sister is the beginning of a fantastic new series. I can't wait for book two, and am crossing my fingers for a television series!