Familiepleje I Denmark by Bryderup, Engen and Kring (2017) is a very ambitious piece of work. The book has more than six hundred pages, and includes a Danish national empirical study of foster carers and foster children, the historical and socio political context of this type of care, a comparative sub study of care in Norway, Sweden and England in relation to Denmark, as well as an extensive review of research on foster care and children in placement. According to the authors, too little is known about the foster care system and the children in it. Therefore, the overall aim of the book is to bring knowledge to a field with big knowledge gaps.