First a note to people who have come across this book and aren't familiar with the series: you will need to read others in the series first in order to get the most out of this book; much of what Frevisse is doing is in particular dependent on the previous volume. While the general plot and the curiosity of having Jews in England will still be interesting even if you are unfamiliar with the series, you will enjoy far more about Dame Frevisse's thoughts if you know more of the background. So while you are ordering this book, go ahead and order the previous one in the series "The Widow's Tale," and a couple of others; if you can't get the whole series right now, then for choice, I'd suggest "The Bishop's Tale" and "The Maiden's Tale" (the latter is set in London and in the family of Frevisse's cousin Alice, and sets up a lot of the necessary information for enjoying "The Widow's Tale").
The editorial reviews and other reviewers have outlined the plot, so I won't repeat that; let me instead mention a few things I enjoyed in particular about this book, that made it more than just an OK continuation of a series.
First, the Author's Note at the end of the book, which explains such details as why this is "The Sempster's Tale" rather than "The Seamstress's Tale." Other bits of information about the state of the English language at the time are also included. The period of time in the mid-15th century was seeing the Middle English of Chaucer (Dame Frevisse's great-uncle) slowly but surely change into the Early Modern English that would become Shakespeare, and I enjoy knowing some of the details of the evolution of words.
Then, there's the way that during the story, we learn about the differences between friars and monks - something that in our own time, we think of as being the same thing; in fact, they weren't. We also learn more about a priest's duties, and the curious fact, from our modern point of view, that priests are in some ways considered inferior to friars. The Inquisition is being powered by friars and monks more than by priests. In our own time, we thing of the various orders of priests such as Jesuits as being the religious who are really learned and sharp, so it is something of a shock to find that in Frevisse's era, the friars were the really learned ones, and priests who just stayed in one place to celebrate Masses for lay people were far less powerful or respected.
We also find out some details about Frevisse's childhood, that help us understand her strength of mind and her adaptability to travel, more than most women in a convent.
For many history buffs, the larger action of the rebels in London will be the most interesting part; for me, that was just background, and I think that other than providing a reason for people to be either holed up in their houses or leaving London, the fighting and the reasons for the rebellion are just background, not as interesting as the many details of daily life that we get, as we do in every novel in this series. From how servants are treated to how money is exchanged internationally, I continue to be fascinated by the working lives of every character in these books. The introduction of new characters - particularly, in this volume, secret Jews and various different levels of converts from Judaism to Christianity - is one of the things I look forward to in each volume. Even the rather repellent characters, such as Brother Michael the friar, are interesting and have information about them that I enjoy learning.