The Aldens are helping save an old library that's about to be torn down. If they fix it up, it might be given landmark status! But after all their hard work, it's very clear someone is trying to destroy the library. But who?

The Aldens are going with grandfather to visit his friend, old Cap Lambert, a retired riverboat pilot who lives in a cabin in the woods. To get there, the Boxcar Children take a wonderful trip down the Mississippi in a paddlewheel boat. But when they arrive at Cap Lambert’s cabin, they find some mysterious things are going on. Spooky phone calls, eerie flickering lights, strange dark figures. Is the cabin haunted?

Benny and Henry are working all summer at Furman’s, the biggest store in town, but they hadn’t expected that solving mysteries would be part of their job! When an expensive vase disappears, the salespeople receive odd notes, and the jewelry display is tampered with, it’s up to Benny to uncover the truth!

The Alden family is spending sunny days at the shore and summer nights in the mobile home right on the beach! One morning Benny finds a gold necklace in the sand, and a search for its owner begins a trail of clues that leads to Tower House, the strange old mansion nearby. What will the Boxcar Children find there?

The Aldens have found a mystery under their very own roof! When the children found an old journal behind the closet wall in the guest room, they never dreamed it would lead them on a search for valuable coins. What happened to the girl who wrote the journal - and what is she trying to tell them?