The Alden children suspect that the other guests are somehow involved when things begin to disappear where they are staying in Washington, D.C.

While investigating the disappearance of Mr. Woods' beloved cat, the Alden children uncover a number of mysterious suspects in the catnapping

When the Aldens go to the Pickering Natural History Museum to assist with the opening of a dinosaur exhibit, their work is hampered by a series of mysterious happenings.

The Boxcar Children love exploring the train, watching the beautiful scenery from the observation car, and eating in the dining car. But the train ride gets really interesting when they meet a young woman who has had something very valuable stolen from her. Can the Aldens solve the mystery before the train pulls into the last stop?

The Aldens investigate when the arrival of several suspicious characters in Greenfield coincides with a mystery involving a popular boy actor.

The Aldens are spending a weekend at Goldwin University for Grandfathers college reunion. The children are fascinated by the mysterious clock tower overshadowing campus and they soon learn that the tower might hold the key to a valuable secret from the past! But there are strange lights coming from the clock tower at night. Is it haunted? Or is someone else searching for the secret of Goldwin University?

When the Aldens first arrive in Elbow Bend, they meet Kate Frances, who tells them all sorts of ghost stories about the town! The scariest tale is about a ghost dog who howls at midnight and appears to warn people of danger! The Aldens think it is just a story until they hear dogs all over Elbow Bend howling at midnight. Does the ghost dog really exist or is someone playing a trick on them? The Boxcar Children are determined to find out.

While visiting an old mansion, the Aldens investigate the possibility that it may be haunted.

When the Aldens have the chance to work at a candy factory, they try to find out who is sabotaging the candy and why.

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!