This is not your usual Mark Billingham. Yes, there are a few murders. Yes, there is a mystery to solve. And yet the setting (a mental health institution) gives this book a totally different flavour and feel. Very realistic, very well done.
Oh, and PS: I really like Tom Thorne makes an appearance in person, even if his name isn't mentioned.
PS2: Alice down the rabbit hole, Mad Hatter's tea party yep, got it.