Someone or something is making a mysterious tapping sound at midnight in the home of a famous inventor known for her one-of-a-kind clocks. There is an invention convention taking place in the home and the Alden children are competitors at the convention. Does the mysterious tapping mean trouble for the convention? The children are determined to find out.

The Aldens take part in a hunt at a gem mine and discover that someone is out to sabotage the contest.

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

A family ghost may be back in Wisconsin! Henry, Jessie, Violet, and Benny discover a mystery that comes with its very own ghost story! When the children visit an old farmhouse, they learn the legend behind a painting there. Long ago, when a traveling artist painted a scene from the farm, he saw something that shouldn't have been there -- the family cow, who had run away years before. Did the artist see a ghost? And now the owner of the house has discovered...

The zoo is wonderful -- it has seals and giraffes and elephants and tigers, and Benny's favorite, a little monkey named Amos. It also has a mystery. Someone is mixing up signs, switching off electricity, and endangering the animals' lives. If the Boxcar Children want to save the animals, they'll have to solve the mystery -- and fast!

The Aldens are spending a week at a rescue ranch that takes in horses whose owners can no longer care for them. The children help with chores, and Jessie looks after a horse named Dragon. But soon two of the oldest horses are missing from the pasture.

When the Aldens visit Peggy and Doc Firmin's farm, they're in for a treat: a behind-the-scenes look at a real teddy bear workshop! But a very rare and valuable bear has disappeared from the toy hospital. Now it's up to the children to track down the teddy thief!

The Aldens have been chosen to be on an exciting new game show, but as they search for clues around the city of Philadelphia, someone is trying to give them the wrong directions.

While staying at the Winding River Lodge, the Alden siblings investigate tales of a zombie haunting a lake in the woods.

When their grandfather buys a bookstore at auction in New Orleans, the Alden children help clean it up and discover that several people seem to be obsessed with the store and its contents.