House of Hollow - Krystal Sutherland - paperback

Horror standalone

When Iris was a child, she and her sisters disappeared, only to reappear a month later, with no memory of what happened to them. No years later, has to find her oldest sister Grey, who has disappeared again. 

Together with her sister Vivi, they start following the bread crumbs Grey has left behind. The supernatural starts knocking at their door, and mysterious things start to happen.

Irene's note: this book is absolutely incredible, I loved the story, the horror elements and the overall gloomy setting.