The American writer credited with more than thirty children's books wrote the third installment of what?
Messenger (novel): Messenger is a 2004 young adult fiction by author Lois Lowry. Messenger (novel):  It forms the third installment of "The Giver Quartet" begun by her 1993 Newbery Medal-winning novel "The Giver". Lois Lowry: Lois Lowry (born Lois Ann Hammersberg; March 20, 1937) is an American writer credited with more than thirty children's books.
The Giver Quartet