What Happened in Marston.  New York:  Four Winds, 1971.

Berlin: City Split in Two.  New York:  Putnam, 1971.

The Loners.  New York:  Viking, 1972.

Vampires. Philadelphia:  Lippincott, 1973.

Werewolves.  Philadelphia:  Lippincott, 1973.

Witches.  Philadelphia:  Lippincott, 1975.

Demons and Devils.  Philadelphia:  Lippincott, 1976.

Fun with Forecasting Weather.  Boston:  Houghton, 1977.

Fours Crossing.  New York:  Farrar, Straus, 1981.

The Kids' Code and Cipher Book.  New York:  Holt, 1981.

Maria's Mountain.  New York:  Houghton, 1981.

Annie on My Mind.  New York:  Farrar, Straus, 1982.

(Adaptor) Favorite Tales from Grimm.  New York:  Four Winds, 1982.

Watersmeet.  New York:  Farrar, Straus, 1983.

Prisoner of Vampires.  New York:  Farrar, Straus, 1984.

Peace, O River.  New York:  Farrar, Straus, 1986.

The Door Between.  New York:  Farrar, Straus, 1987.

Mystery of the Night Raiders.  New York:  Farrar, Straus, 1987.

Mystery of the Midnight Menace.  New York:  Farrar, Straus, 1988.

Mystery of the Secret Marks.  New York:  Farrar, Straus, 1989.

Lark in the Morning.  New York:  Farrar, Straus, 1991.

My Sister, the Vampire.  New York:  Knopf, 1992.

Mystery of the Kidnapped Kidnapper.  New York:  Minstrel, 1994.

Mystery of the Watchful Witches.  New York:  Minstrel, 1994.

Dove and Sword: A Novel of Joan of Arc.  New York:  Farrar, Straus, 1995.

My Brother, the Werewolf.  New York:  Bullseye Books, 1995.

Good Moon Rising.  New York:  Farrar, Straus, 1996.

The Year They Burned the Books.  New York:  Farrar, Straus, 1999.

Holly's Secret .  New York:  Farrar, Straus, 2000.

Molly's Family.  New York:  Farrar, Straus, 2001.

Case of the Stolen Scarab: A Candlestone Inn Mystery.  Ridley Park, PA:  Two Live Pub., 2002.

Meeting Melanie .  New York:  Farrar, Straus, 2002.