Blackwork by Monica Ferris is the thirteenth book in the Needlecraft Mystery series. One of Betsy's Monday Brunch club is a practicing Wiccan and while that's never been a problem before, someone has started spreading rumors about her practicing black magic. Then a frienemy of hers is found dead in his his locked room and everyone wants to believe that Leona Cunningham, brewery owner and Wiccan, put a curse on him.
The vitriol spewed over Leona's religion seemed out of place for the characters caught up in it. Sure Betsy is a regular church goer as are a number of her friends but the church as described doesn't seem like the place that would foster such paranoia.
Ignoring the idiotic Halloween themed set up, Ryan's death in a closed room is an interesting, albeit, recognizable mystery. Closed room mysteries are the meat and potatoes of the genre. The question then becomes what was put in the room before he got there and how does it work to leave little or no trace of itself?
Basically this book's main flaw is its holiday theming. Get enough books in a series and there's always the temptation (publisher's demands?) for holiday themed plots. Sure, a holiday themed book can be put on display at the appropriate time in bookstores and libraries. But these holiday themed books more often than not feel forced.
Blackwork is one of those books that except for the witchcraft paranoia leading up to Halloween, doesn't need to be set at any particular time of the year. Betsy working on the fall festival committee could be doing this in almost any of the books in this series. Even the title isn't specific to Halloween; it's a type of very careful stitchery done against a contrasting (typically, though blue on blue is apparently also acceptable) background. It's something that would be stylish any time of the year.