Part of the Shadow Children series in which third born children must stay in hiding in order to escape certain death at the hands of the Population Police, many characters return, including Mr. Talbot and Nina, and some of the plot elements of previous books reappear. While there is little character development, the book is fast paced, opening with a raid on the Niedler School that forces Matthias, Percy, and Alia to run for their lives. The two younger children are injured and Matthias inadvertently becomes a member of the Population Police. Issues of trust and loyalty will appeal to readers as will the twists and turns of the action. This book also contains many references to faith in God and the need to believe. Matthias often finds peace and strength in thinking of the advice given to him by his surrogate father, Samuel, a man of great faith. This one is for fans of the books before.