Alex and Leslie Twisden are a golden couple with money, good jobs, and a beautiful home. Their big problem - they can't conceive a child. Hearing of a doctor in Slovenia who works miracles for infertile couples they hop a plane to get the treatments. Fast forward ten years and the Twisdens have boy and girl twins but something is wrong. Their home is a wreck, they're almost broke, they avoid social interactions, and they always lock their children's bedroom doors at night.
Turns out the Slovenian doctor's methods were unorthodox and resulted in frightening side effects. The twins make a break for it, seek help, and happen to come across other families like theirs. As a result they see some disgusting and horrific things. There's plenty of blood and gore and tragedy in this page turner but I was dissatisfied with the ending which (I felt) didn't wrap up the story properly. Perhaps there will be a sequel.