The focus turns to Robin - as someone decides that he is going to kill “The Secretary” as a means of getting even with Strike. It’s a solid premise but the execution left me wanting more. We start with Robin receiving a severed leg in a box, brought to Strike’s office from a bicycle delivery person. The press catches on to the incident - and Strike starts losing clients. 
Strike thinks of three people who might be capable of sending a severed leg - and starts his own investigation in addition to the official police inquiry. Interspersed with the Strike and Robin chapters, are the chapters with the man stalking Robin who refers to the woman he lives with as “It”.  These chapters were never creepy enough - and while they gave a few red herrings - I kept thinking that Galbraith could have learned from John Sandford or maybe Lincoln Child about inserting chapters from the bad guy’s pov.  
We learn some more of Strike’s background, meeting his friend Shanker and his step-father Whittaker. Robin fights with Matthew and temporarily breaks their engagement.  

The book has some loose ends that annoyed me. Robin receives a dozen roses delivered to the office after Matthew has been home alone for his dad’s birthday. She never looks at the card attached to the flowers - so we don’t know if they are from Matthew - or the stalker/killer. When Strike figures out that the killer is Laing - who is leading a double life - we haven’t had much interaction with Laing as  Ray Williams - living with the older sister of the girl who’s severed leg was sent to Robin - beyond the visit Strike made to see Hazel. The Laing narrative was incomplete - especially when I think about all the red herrings pointing your thoughts to Whittaker and Stephanie.

The ending certainly sets up Strike for continuing to solve cases with Robin.