Four girls who attend a Catholic boarding school in a convent form a tight friendship to assuage their longing for the family members who abandoned them. Told through the 1st-person view of one of the girls looking back to when she was 15, and the events that marked their quiet, devout, ritualistic life. 
 Each of the girl's personalities are fleshed out and distinct. Their dialogue is believable as sheltered Catholic girls; they all believe the doctrine that they are force-fed daily, but that doesn't mean they like being there. They long to be out in the world and do as they wish; but they have nowhere to go. When wounded, comatose soldiers without an identity are brought to the convent's convalescence ward where the girls work shifts, the girls become obsessed with them, transferring their ideas of love and a hopeful future onto the boys...but also wondering how could God let such a bad thing happen to these boys. 
 This is a contemplative, slow-paced coming-of-age. Some readers might find it slow. I would not recommend it to readers who do not want to be immersed in Catholicism. Other readers who are very into Catholicism might take issue with the accuracy of some things, like how likely is it that four girls would be asked to be alter servers years before one of the Popes made that a thing in the 60's. 
 Some readers have guessed this to take place during WWII but it might also be during the Korean War. We know at the end that it is almost 18 years later and girls are allowed to be alter servers now. The convent rec room only had an old radio, there was no t.v., (and no mention of t.v.), but in the 50's a lot of people still did not own a t.v. Especially a secluded convent would not have one; so it could be during WWII, but it could be later too. 
 It should be noted that this novel achieves realistic depictions of the religious authorities (which is rare in books). There are no evil, oppressive nuns or priests here; if you are looking for a scandalous drama look elsewhere. Nor are they overly earnest. The priest is flawed and alcoholic; the main nun, Sister Fran, is strict but believes in her calling and rules with the girls well-being in mind. 
 Guinevere is not the most exciting protagonist, but she is consistent and believable. I don't know why we got a glimpse into her backstory all the way at the end, that should have been sooner. If you like observations through a young girl's eyes trying to make sense of the world, and a church setting, go for it.