The Convivial Codfish by Charlotte MacLeod

Not a lot of Sarah in this book and I definitely felt her absence. Instead, the focus is Max as he infiltrates a Christmas party hosted by one of the men in the Comrades of the Convivial Codfish, Tom Tolbathy. He does it to help out one of Sarah’s many uncles, Jeremy. It seems that Jeremy, who is the current Exalted Chowderhead, lost the ceremonial chain at a recent Dickens Christmas Carol dinner. Jem can’t go to the party himself because he fell down the stairs at his house and broke his hip, very nearly his head. Max is sent in his place to see if he can recognize the chain. And he does but the party (on a train, by the way, so cool) goes horribly wrong when the train stops suddenly. Tom’s brother is found dead and the rest of the party starts failing, a result of poisoning. 

Lots of big words which are great for vocabulary building and a good story but not fairly clued - even the last big hint is kept cloaked. And the relationship between Sarah and Max is one of the draws of the series but it was almost nonexistent in the book.

Three stars
Follows The Bilbao Looking Glass
Followed by The Plain Old Man
This book came out 1984
Borrowed this book from the library
Opinions are my own