While visiting a Navaho Indian reservation in New Mexico, the Aldens try to save a forest under threat of development by proving it is the site of a lost, buried village, but someone is sabotaging their dig.

The Boxcar Children investigate when everything seems to go wrong for the Greenfield Museum as soon as the Museum displays a four-thousand-year-old ancient Egyptian mummy.

When an elderly friend is injured, the Alden children offer to help him with his window-washing business in their small town of Greenfield and agree to help him solve a riddle that has arrived in a mysterious invitation.

While visiting Lake Lucille in the Adirondack Mountains, the Aldens hear stories about a monster in the lake and then encounter evidence that it may be real.

While on a camping trip with their grandfather, the Alden children try to find out about the loud music and missing food that threatens to scare away other campers.

The Aldens are excited to be playing in their summer soccer league, until someone begins sabotaging the teams.

Henry, Jessie, Violet, and Benny decide to investigate when they travel with their grandfather to buy honey at the Sherman's honey farm only to discover that the bees, for some reason, have quit making honey.

While staying at an eighteenth-century inn in Vermont, the Boxcar children become curious about the mysterious "accidents" that keep plaguing the owners.

While visiting Michigan's Upper Peninsula to prepare their Great-aunt Sophie's big old house for sale, the Boxcar Children encounter a mystery involving a valuable ring supposedly hidden somewhere in the house.

The Aldens visit an old camp in Quebec, Canada, and begin to suspect that someone or something is trying to scare them away from the place.