Wow that one blew my mind! It was my second book by Alice Feeney after His & Hers (which I also enjoyed!) and I loved every second of it! It was so so good! 
It's the perfect winter thriller with several POV's and timelines. Adam has a condition called face blindness and it adds something extra and mysterious to the story. The overall setting in the remote, scottish, snowy forrest & an old chapel turned into a home was so picturesque I looooved it! For me everything was in the right place and I devoured this one! I can happily say that this book just got a place on my shelf for my all time favourite books! Definitely going to do a reread.