Early publications , 1947 After dropping out of college, Duncan continued to write and publish magazine articles; she wrote over 300 articles published in magazines such as ''
Ladies' Home Journal, Redbook, McCall's, Good Housekeeping, and Reader's Digest. followed by Debutante Hill'' in 1959; While teaching, Duncan enrolled in classes at the university, earning her
Bachelor of Arts in English in 1977. In 1970, she published the
historical novel Peggy, chronicling the life of
Peggy Shippen, followed by the 1971 children's book
Hotel for Dogs, which was later
adapted as a
2009 film of the same name starring
Emma Roberts.
Suspense and horror novels Influenced by her own interest in the
supernatural and
speculative fiction, Duncan wrote various suspense and horror novels aimed for teenagers. After the publication of
I Know What You Did Last Summer, Duncan wrote
Down a Dark Hall (1974), a
Gothic novel following four students at an isolated and mysterious boarding school. In 1976, she published the supernatural horror novel
Summer of Fear, which was also adapted into a 1978 film by director
Wes Craven. In 1978, Duncan published the controversial
Killing Mr. Griffin, a novel that details three high-school students' murder of their English teacher. Critic
Margery Fisher noted Duncan's "unreserved" approach to writing the novel, in language she described as both "harsh and literal."
Richard Peck of
The New York Times also praised the novel, writing: "Duncan breaks some new ground in a novel without sex, drugs, or black leather jackets, but the taboo she tampers with is far more potent and pervasive: the unleashed fury of the permissively reared against any assault on their egos and authority ... The value of the book lies in the twisted logic of the teenagers and how easily they can justify anything."
Killing Mr. Griffin was one of Duncan's major critical successes, and was selected as an
American Library Association Best Book for Young Adults that year. In the 1980s, Duncan would publish several more horror novels with supernatural themes, including
Stranger with My Face (1981), about a teenage girl's experiences with
astral projection, and
The Third Eye (1984), also with psychic themes. In 1985, she wrote another suspense novel,
Locked in Time.
Later works In 1988 and 1989, Duncan published the thriller novels
The Twisted Window and ''
Don't Look Behind You, respectively. From 1987 to 1989, Duncan wrote several picture books for young children, some paired with audio CDs of songs for children, including Songs from Dreamland
, Dream Songs from Yesterday
, Our Beautiful Day
, and The Story of Christmas''. After the
murder of her youngest daughter, Kaitlyn, in 1989, she only wrote one more horror novel, a supernatural thriller titled
Gallows Hill (1997). The murder of Duncan's daughter marked a shift in her writing, and she spent the remainder of her career writing thematically lighter material, mainly children's chapter and
picture books. Beginning in 2010, ten of Duncan's most successful teen novels were updated for a new generation and re-released in paperback with modern cover designs. For the new editions, Duncan gave characters updated wardrobes, more contemporary dialogue, and access to technologies such as cell phones. ==Personal life==