This completes the set that began with Farthing and continued with Ha'penny. Some of the characters are ongoing, but the story is mostly self contained. (I reviewed Farthing but I can't find it right now. Why can't I Google my own public entries? They're supposed to be searchable.)
It's pretty much impossible to say anything at all about this novel and the conclusion of the trilogy without some spoilers. It's actually implicit in the fact that this is the third book in the trilogy; if the first book was the beginning of something and the second book was the middle, the third book has to be in some sense the end. The real gut-wrenching power of Farthing was in just how easily believable it was. Perhaps it's just my own pessimistic attitude, but I found the plot of Farthing not just conceivable but actually likely. Half a Crown's plot is fine for a novel but it doesn't hit me with that feeling of inevitability that that's just how it would really happen. There's a good adventure, real drama, and a lot of characters struggling with their own flaws, trying to figure out the right thing to do in an imperfect world. It's a solid book; I think the actual characters and the story just as a self contained story might even be better than Farthing. It just doesn't have the same level of political impact.
To put it another way, I think Farthing was a book that everyone needs to read, whether they like it or not. Ha'penny and Half a Crown are optional. Setting aside the political importance for a moment, though, Farthing was a good book, Ha'penny a little weaker, and Half a Crown back to being good. They make a good set.
8 out of 10.
**** PLOT SUMMARY -- MASSIVE SPOILERS ****
It's 1960, about 10 years after the last book. Elvira Royston, the daughter of the policeman who died in the first book, has been adopted by Carmichael, now Watch Commander. He's provided the money and a little bit of respectability to make her a debutante. She's paired with Betsy, an impoverished blue-blood; Carmichael's money has gotten both of them through finishing school and they're about to be presented to the Queen when they get caught up in interesting times. Sir Alan, the dark mysterious stranger, is a bit of an agitator. He takes the girls to a fascist rally where a riot breaks out. The Duke of Windsor, Edward VIII before he abdicated to marry Wallis Simpson, is plotting a coup, on the grounds that England isn't being fascist enough (and of course he'd like to be King, none of this constitutional monarchy nonsense, really in charge). This, combined with his own paranoia, causes Prime Minister Normanby to crack down in a very draconian manner on the rioters. Elvira gets arrested, and Normanby decides to use her to test whether Carmichael is really loyal. Since Carmichael is gay and Normanby knows it, Normanby still has Carmichael's soul, but Carmichael has been using his position to secretly smuggle Jews out of Britain. Rather than let his adopted daughter be sent to the German concentration camps (and possibly reveal some hint of the secret Inner Watch on the way), Carmichael uses his own power to openly oppose Normanby, and bites off more than he can chew. He grabs Elvira by force and puts her into the safe house system, but the safe house gets broken. Elvira escapes and finds her estranged mother, who helps her to arrange to rejoin Betsy and keep her scheduled appointment to be presented to the Queen. At her formal presentation, she gives the special signal that she actually has something to *say* to the Queen, and blurts out the story in her audience. As this was going down, Carmichael's lover Jack got arrested and suicided with his hollow tooth. Carmichael handed over his evidence of Normanby's guilt to Sir Guy. Sir Guy brought it to the Queen, but it was only in combination with Elvira's testimony that really got the Queen fired up. Carmichael found himself arrested and tried to use his own tooth, but it turned out he was being taken by his own people in the Watch after the conspiracy was broken, and they knew about the tooth and managed to keep him from using it. Both the new usurpation by the Duke of Windsor and the old usurpation by the Farthing Set are put down as the Queen dissolves Parliament and calls for new elections.