The Aldens investigate when a new store called the Game Spot opens in town and the neighboring shops are robbed.

"The Aldens are spending their first week of summer at Camp Quest in Colorado. The children are excited to learn about fossil hunting and paleontology from renowned scientist Dr. Iris Perez. But strange events at the camp make them wonder if the legends of a bigfoot-like creature roaming the valley might be more fact than fiction. Can the Aldens help Dr. Iris figure out who - or what - is causing such a stir?"--Amazon.

"The Aldens have joined Dr. Iris Perez as she investigates legendary creatures around the world. In this adventure, the children travel to Iceland to look into stories of mischievous elves causing trouble. The legends of huldufolk, or hidden people, go back a long way in the country, but are elves really the cause of the problems, or is there a more natural explanation for the strange events on the island?"--Amazon.

After a series of strange events, the Alden children must solve a mystery to help their friend Mike and his family.

While helping their grandfather prepare for Greenfield's Winter Festival, the Alden children uncover a mystery surrounding the statue in the town square.

The Aldens investigate when the new coach of their community basketball league has her Most Valuable Player trophy stolen.

The Aldens try to solve a series of mysteries which took place in a old hotel in Kansas which they visit.

The Aldens investigate when exotic and endangered animals begin to disappear from the zoo where their new friend Lindsey works.

The Aldens visit Grandfather's friend at the Ogopogo Retreat and aided by puzzling clues, embark on a treasure hunt to prevent the retreat from being sold.

The Aldens start a business producing birthday parties and find themselves investigating a series of robberies taking place during their parties.