Mary Russell is reluctantly dragged away from her studies after receiving a telegram from Holmes requesting her presence in Dartmoor. Holmes had been in Dartmoor visiting an old friend, but got drawn into an investigation after a local is killed. The case in question involves a ghostly carriage made of bones and a spectral hound haunting the Moor. Rather begrudgingly, Mary helps to scout for clues in the foggy, cold, and damp Moor. What both her and Holmes find are a handful of supernatural sightings that draw suspicious parallels between this case and one of Holmes' most famous investigations, The Hound of the Baskervilles.
Like a lot of Sherlock Holmes fans, The Hound of the Baskervilles holds a special place in my heart. So revisiting the setting of that mystery with Mary and Holmes had my geeky heart all a titter.
The pacing here was a lot faster than in some of the other Mary Russell books, which was a relief after slogging through the slow moving A Letter of Mary. My only complaint is pretty mild, Mary was going through a bit of a mid-life crisis that involved a hesitance to fully join Holmes in the case until near the end. So she sort of emotionally checked out during the first half of the investigation. While she was still physically involved, there was a lot of background noise involving her reluctance to be there at all. King did a good job of attributing this to a psychological backlash due to the events of the previous three books but, with such an awesome mystery going on, I got frustrated that Mary wasn't getting into it. However, Holmes more than made up for Mary's standoffish attitude. He was, luckily, more present here than he had been in the previous books and seemed really in his element. It was great seeing Holmes get to dash about and really get into the mystery, which is something we hadn't fully gotten to see in the first three novels.
Most of the action takes place in a huge echoing mansion and the chilly moor, which seems so far removed from the London/Sussex settings of the previous novels that it was a refreshing change. I also really adored the moor atmosphere because I'm a huge fan of Gothic mysteries. The moor offered a great eerie and isolated feeling typically found in that genre and it really upped the suspense.
This is, by far, my favorite out of the series so far. I highly recommend it.