This kind of story has all the makings of silly, sappy and useless. Instead, the authors have used this open framework to subtly deal with a lot of difficult problems. Marginalized people populate the book, as do those who accept and assist them: Juliet, an orphan, Kit, an illegitimate orphan fathered by an occupying German, Dawsey with his language and speech difficulties, Isola with her wild appearance and social difficulties, Sidney (who is homosexual), John Booker (who is definitely Jewish and I think is also homosexual, altho Isola is not the most reliable witness). Everyone on the island of Guernsey is the descendant of the marginalized: not in England, not in France, left largely to themselves, both free and unprotected, descendants of pirates, smugglers and others who live on the margin through choice or necessity.
The story of the slave workers brought in by the Germans to fortify the islands provides both a mechanism for sending the passionate and heroic Elizabeth to a concentration camp, and an illustration of the difficult decisions made every day by those surviving the occupation. Surely the islanders were justified in protecting their gardens; but the slaves who were foraging died because they had no food. Peter's decision to try to save one risked himself and Elizabeth. Peter's own handicapped status proved a greater protection for him than Elizabeth being a woman. Our book group weighed the question of whether Elizabeth should have squashed her protective instincts once she had a daughter of her own to look after, further illustrating the difficulties met every day even by people "comparatively" unscathed by the war.
Remy provides an ending to the story of Elizabeth, and also brings along the opportunity to depict the aftermath of surviving a concentration camp: the total loss of her family, the inclination of her fellow Frenchmen and Frenchwomen to supply a small amount of financial support to survivors but otherwise pretend this chapter in French history did not happen -- even tho the Vichy government and many others in France participated in identifying Jews.
Over the last decade, as many of those who survived the war entered their 80s, this kind of discussion has become more and more possible, but it continues to be difficult. Europe has been rebuilt long enough that the physical devastation and the deprivations of the war are barely within living memory. The longstanding cultural gear mashing that led to two world wars are all but unimaginable with the success of the EU (notwithstanding constant commentary that constitutional crises will somehow bring it down). It is easier to teach in school the simple stories of the Allies and the Axis. It is difficult to explain what names like Quisling and Vichy once meant. It is impossible to run the list of percentage of Jews dead by country and still include the Diary of Anne Frank as recommended reading material in junior high school.
Now, all but a tiny few of the men who liberated the camps are dead. Their children, and the children of the survivors continue to bear scars from that war: family stories of loss and betrayal and unimaginable decisions and their horrifying consequences, which included not telling those stories because it was more important to rebuild, and carry on, than to dwell on the impossibly painful past.
It may always be necessary to couch these stories in a lighthearted framework, if they are ever to be told at all. After all, the Adelaides of this world are too good for everyday wear.
I'm still trying to decide whether the decidedly post-modern self-interpretative framework supplied by the conversation between Juliet and Sidney over how to structure Juliet's book is just way too clever by half, or a subtle, nuanced little Easter Egg for the literarily alert.
Should you read it? Heck yeah! Pretty painless, all things considered, you'll inevitably learn something, and if you pay attention, you might even be impressed. But even if you just amble through it casually, I suspect that just reading a book about the German occupiers that doesn't use the word Nazis will work a little magic all its own. This sucker has the potential to really highlight that the problem presented by that war wasn't about some fascistic ideology per se. It was about lockstep pressure to hyperconform -- the problem suffered by institutions and empires in all times and places. One must be careful not to succumb to the same problem when fighting back.
No matter how tempting.
ETA: Oh, yeah. If you expect your historical novels to sound correct for the time period, prepare for cringing. Her telegrams are too long and do not contain the word stop, ever. No one who had to actually pay for a telegram would write the ones in this book.