Firefly & Fern

Mark Fowler, Radhi Parekh

Ages 9–15logic and reasoningproblem-solving

Penny Warner

Ages 8–12mysteryadventure

John C. Ford

Ages 12–16problem-solvingadventure

Barbara Dee

Ages 8–12family relationshipscryptography

Elizabeth James

Ages 8–12cryptographyproblem-solving

Penny Warner

Ages 8–12mysteryproblem-solving

Penny Warner

Ages 9–13mysteryproblem-solving

Simon Singh

Ages 10–16cryptographyproblem-solving

Liza Mundy

Ages 12–18women in historycryptography

Gary L. Blackwood

Ages 9–14cryptographyhistory