I loved it, but I'd be very cautious about recommending this book because I don't think that it is what people are expecting after book #1 & #2 and because it is on the fringe of the romance genre, even if Tom's and Stanley's romance is still well alive.
I don't know yet how the series will develop, but it sounded like this 3rd book was in brackets, like the author was taking stock or something. It's full of interrogations and reflections about life, love, sexuality, what brings people together, about relationships, with depressing thoughts too about ageing and people who will never find solace, redemption or accomplishment. And don't we have enough of that in real life, already? Still, I loved it.
The mystery is a psychological thriller rather than a whodunnit, since we get to follow the murderer as much as Tom and Stanley. It's always a question of when and how rather than a question of who. The construction and those themes are not new in the series, but it's more open in this one, heavier, more chilling somehow, as Banis takes his time to linger on them and tones Stanley's antics down. There is little humor to offset the pervading melancholy.
I found the climax disappointing and the outcome contrived and melodramatic, but before this very last part, I loved the writing, the thoughts, the construction; and it felt good to be engrossed in a book and to devour it. So, 4 stars.