The Alden children travel on a Mississippi paddle-wheel steamer to visit an old family friend in his cabin near Hannibal, Missouri, and try to discover who is responsible for the mysterious activities near the house.

Bad luck hits the Greenfield Museum with the addition of an ancient mummy exhibit. Annotation. The Aldens are helping the museum curator set up an exhibit about life in ancient Egypt. But the longer the Aldens are around the exhibit's mummy, the more things go wrong. Has the museum been struck by a curse from the ancient mummy? Illustrations.

During a trip to Oregon, the Aldens are astonished when Watch discovers a backpack filled with valuables, a finding that compels them to learn what happened and return the backpack to its rightful owner.

"The Aldens try out a Halloween escape room. The puzzle are fun to solve. But when eerie events start scaring people away, the children find a much bigger case to crack." --

"Henry, Jessie, Violet, and Benny used to live in a boxcar. Now they have adventures everywhere they go. At a lighthouse, the children find a mystery in the night!"

The Aldens are excited to learn about beekeeping. But when equipment goes missing, they have more than honey to harvest -- they have a mystery to solve!

When Henry's magic teacher, The Amazing Arthur, goes missing right before the Greenfield Magic Shop's annual magic show, Henry and his sibilings look into Arthur's disappearance.

Jessie and Henry's robotics team is competing in a big tournament. But when their robot is stolen, the Aldens have a high-tech mystery to decode!

The Alden children are trapped in their cabin by a snowstorm, but while they wait for the storm to pass, they discover the cabin is full of secrets.

The Alden children, isolated in a storm at a small bus station, are led into a mystery centering on a polluted river.