Lowry's work "Number the Stars" was published in 1989, and received multiple awards, including the 1990 Newbery medal. Lowry received the Newbery medal again in 1994, for "The Giver" (1993). After writing "The Giver", she published three companion novels which take place in the same universe: "Gathering Blue" (2000) and "Messenger" (2004) and finally "Son" (2012), which tied all three of the previous books together. As a set, they are considered "The Giver Quartet". The "New York Times" called the quartet "less a speculative fiction than a kind of guide for teaching children (and their parents, if they’re listening carefully) how to be a good person."