At first, the police look to Kyle, as the spouse is always at the top of the suspect list, but Kyle is pushing the police hard to find his wife and they can't do enough, according to him. He even begins his own social media campaign called #FindHannah enlisting local folks to beat the bushes for any clue of her. One such person who joins in is Julie Matthews, who is eager to help a fellow woman from Belfast who could be, she suspects, caught in a "rapist's den." At the first campaign meet-up, she gets friendly with Kyle, who reciprocates with an invite for coffee, and lonely Julie is all too happy to be on the receiving end of gorgeous Kyle's attention. Surely she is imagining it, since his wife is missing, but as it turns out, she isn't and she gets caught up in his sway.
Meanwhile, Detective Kerry Lawlor is tapped by her superior officer, D.I. Simon Peters, to work with him on the Hannah Greer case and they are searching for her tirelessly. Naturally, they both suspect Kyle Greer, but so far, nothing seems to stick to him. Alas, there is also no sign of Hannah anywhere.
Then there's Guy, an aspiring writer who works from home most days, but is also a part-time co-worker of Hannah's, and his girlfriend, Kate. Kate is following the story of the missing young woman with a bit of curiosity and fear, while Guy is oblivious and is focused on his writing, but has befriended Hannah in the past and senses there is more to her quiet and sullen demeanor than she lets on.
Finally, there's Hannah Greer, the victim of the story. Someone's got her in their basement, as an early chapter details her staring up at the feet of passers-by, drugged into oblivion, but who?
Each chapter is told from the perspective of one of the players, be it Kyle, Hannah, Kate, Julie, or Kerry, but typically (aside from two chapters) it is from a female's point of view. The story tracks their various ups and downs in their personal relationships, whether it be Kate's preference not to get married and to keep her relationship with Guy status quo; Kerry's crush on her boss, Simon; Julie's enchantment and then revulsion with Kyle; or Hannah, from the early days of her lovely romance with Kyle, to the point in their marriage when he is literally pushing her down a flight of stairs. Eventually, all of the characters come together to bring the novel to an end.
I will say that while there were some nail-biting moments in the book, to me, Under Your Skin read more like a drama than a thriller. With all of the interpersonal relationship stuff, it just felt like a drama that was built around a missing woman. That's not a ding, mind you, it just wasn't quite a thriller to me. And while it did wrap up, it just felt more like it ended, rather than ended with a bang of a revelation. It is a relatively quick read, though. I read it in two sittings, as it's a little over 200 pages. Some people may be triggered by some of Kyle's behavior detailed in the book. It didn't bother me personally, but your mileage may vary.
