::points to icon:: This is wonderful!! I love how we jump into the story right in the middle of some gripping action and an obviously long-term loving relationship between the two indomitable witches at its heart. Your deft hand with humor conveys all we need to know about these two and how they have each other's back (literally! ::g::). They tease and banter and nurture each other by turns as all of the best of devoted partners do; you can tell that it's the everyday currency of their relationship.
The backstory you create for Kettleburn is harrowing and I liked the interaction with Dippet. He's made to seem rather ineffectual in canon, and he's a much more interesting individual in your hands. Your Galatea rocks ('Old' and 'without use' are not synonymous, indeed!)- she and Griselda are fortunate to have one another. :-) Fantastic work Mystery Author!