Gertrude Chandler Warner Books in Order

A century-old time capsule contains a journal that sends the Aldens searching Greenfield for lost treasure. They must identify its writer and connect historical clues, wondering whether enough evidence has survived to finish the hunt.

A severe storm knocks out the power and leaves the Aldens with a new mystery. Without electricity or internet access, the children must rely on direct observation and old-fashioned detective work to put the clues together.

During spring break, the Aldens help protect endangered sea turtles by marking nests so the eggs can hatch safely. When someone digs up eggs without permission, they investigate the threat to the animals they are trying to save.

The Aldens attend a summer camp where they learn primitive survival skills and explore the wilderness. When strange incidents disrupt the camp, they turn from outdoor lessons to solving the mystery behind the trouble.

Jessie tests a local creek for pollution, hoping her science fair project will help the community. When problems disrupt her experiment, she and her siblings investigate whether someone is interfering with her work.

A shopkeeper has lost his memory after an accident, but someone from his past still holds a grudge. The Aldens investigate his forgotten history, hoping to understand the trouble surrounding a man who cannot explain it.

The Aldens enjoy solving puzzles in a Halloween escape room until eerie incidents begin frightening visitors away. Their game becomes a real investigation as they try to uncover what is happening behind the scares.

A train tour through the Southwest takes a troubling turn when someone revives the lawless spirit of the Old West. Readers choose the Aldens' next steps, shaping whether their investigation reaches a solution or a dead end.

The Aldens help harvest honey at a farm owned by Grandfather's friend and enjoy learning about bees. When repeated mishaps threaten the harvest, they investigate whether someone is deliberately disrupting the work.

Jessie and Benny enter Greenfield's baking competition for children, but mixed-up ingredients and a power failure threaten the event. The Aldens investigate whether these problems are accidents or someone's attempt to stop the contest.

After an oil spill in Connecticut, the Aldens help scientists care for endangered snow leopards. The animals need cool conditions to survive, giving the children another urgent conservation challenge while they assist the rescue effort.

The Aldens travel to Sumatra, where a protected forest is mysteriously being cut down. They investigate who is responsible while trying to protect the orangutans, elephants, and tigers whose homes are disappearing around them.

An oil spill threatens the Connecticut shoreline, and the Aldens join the effort to help affected birds. As they work on the cleanup, the children investigate the disaster and whether it could have been prevented.

In Australia, the Aldens meet conservationist Kayla and learn about the damaged Great Barrier Reef. Helping its animals brings them into a race to restore vulnerable coral, even though rebuilding a reef takes considerable time.

Henry learns tricks from the Amazing Arthur and prepares for the Greenfield Magic Shop's annual show. When his teacher disappears, the Aldens must determine whether they are witnessing another trick or a genuine mystery.

While showing new neighbors around Greenfield, the Aldens discover coded messages in historical documents. Someone wants their investigation stopped, and they must decipher the clues before evidence of their hometown's past disappears.

The Aldens volunteer at a rehabilitation center for wild birds, where suspicious incidents damage its reputation. They investigate possible sabotage, hoping to protect the injured raptors and prevent the center from closing.

While rafting in the Pacific Northwest, the Aldens learn about a mysterious man who disappeared into the wilderness with treasure. Readers choose the children’s next steps as their journey through white-water country becomes a search for answers.