Death in the Highlands by Fliss Chester

Cressidia is invited to the castle for summer vacation.  She is thrilled.

This book was a good read (thank you).  It will be published on June 22nd.

While she is visiting, two men get killed.  She decides to see if she can identify the killer even if the cop wants her to stay out of it.

It takes to the end of the book before the killers are exposed.

There are secret passage ways that allowed the killer to leave the victim there and escape.

Cressidia finds the passages and snoops.  She does get hit in the head and it takes a bit before she can begin again.

The killers were a surprise to me.  Did you figure it out?