Although I enjoyed this book (it's a good bet I'll enjoy anything Hayder has written), it didn't grab me like some of her others have. Possibly that's because it felt a little slow to me; I didn't fall completely into it until I was two-thirds through. Or possibly it's because I wanted more of something -- more development of Oaksey, or of his wife, Lexie, or more time spent on the island with the villagers. Something. 
 What Hayder does get right, as usual, is her narrative structure. Pig Island alternates first person diary/letter-style narratives, one from Oaksey and the second from Lexie (most in the form of letters to her therapist, which are abnormally detailed [including dialogue] than a letter one might write to her therapist, but, whatever, it's a thriller, I don't care). I loved this alternating p.o.v. and it was an interesting way to slow down the pace when the story called for it. 
 If you read Hayder's Hanging Hill and enjoyed the ending (and maybe yelled at the book at little bit), then read Pig Island. And if you finish Pig Island and really like the ending, read Hanging Hill