It is important, when killing a nun, to ensure that you bring an army of sufficient size. So begins Red Sister by Mark Lawrence. Nona Grey lives on an ice world where humanity huddles around the equator and jealously guards its remaining resources. Nona is a slave sentenced to hang for murdering a nobleman. She's ten years old. Abbess Glass of the Sweet Mercy Convent rescues her and Nona becomes a novice. There are ultimately three paths the nuns can choose, but for ten years Nona and the other novices learn the basics of combat, magic, and prayer. Political fallout from Nona's rescue, assassination attempts, and an ancient prophecy combine to add intrigue to a tale of friendship, growing up, and kick ass nuns.

Lawrence has created an intriguing setting. The dying red sun, the artificial moon that concentrates that sunlight and directs it to the equator, and people who pray that the ice can be held back another generation. Against that desperate background Nona stands out. Despite a violent background she has youth's belief in her own immortality. Now that she's at Sweet Mercy she seems to embrace school life as much as Harry Potter ever did. But as she grows older she slowly realizes that the nuns, novices, abbey, and even her world, all have deeper pasts than she saw at age ten. Nona herself is more than she knew. The slaver suspected her of having the old Hunska blood which is known for its quick agility and would be a real advantage to a Red Sister as the warrior nuns are called. But its not unknown for people to have more than one of the four old races in their heritage. Nor is Nona the only talented girl in the novitiate. She becomes best friends with her opposite, a wealthy girl related to the emperor who is believed to fill a prophecy.

The writing is excellent. The style is slightly less grim than Lawrence's Broken Empire series but still contains plenty of blood and violence. He uses both flash forward and flashbacks to fill out Nona's character and what is at stake for the sisters of Sweet Mercy. Because the opening scene is many years forward, Nona's entire story might be considered a flashback. Whether or not the idea for an all female cast of characters is in response to criticism of his previous books, almost entirely male, they are very realistic in their personalities and interactions. If you liked Blood Song by Anthony Ryan this should be good, and vice versa, unless like one reviewer you just don't care for an all young female cast that has some actual young female dialog.

Reviews of Heather O'Neill's narration are mixed. Apparently some people didn't care for her Irish accent although many praised the individual voices she gave each character.

Sadly, book 2, Grey Sister isn't out until April 3, 2018. At least Red Sister resolves the main intrigue and comes to a natural break in the storyline.