Henry, Jessie, Violet, and Benny didn't think the old trunk in their house held anything interesting. But an unusual statue they find inside leads them to the Reddimus Society, a secret guild dedicated to returning lost treasures to where they belong. Now the Aldens must help their new friends by traveling across the country with the statue and six mysterious boxes! Can the Boxcar Children keep these seven treasures out of the wrong hands?

This volume includes: The Animal Shelter Mystery, The Old Motel Mystery, and The Mystery of the Hidden Painting. In The Mystery of the Hidden Painting, the Aldens find a mysterious painting hidden in the attic. The children learn that it is a portrait of their grandmother, whom they never knew, wearing the necklace Grandfather gave her when they were married. The necklace disappeared on their first anniversary - and was never found. Can the Boxcar Children track down a necklace missing for so many years?

Three complete stories in one collection! Includes Mystery in the Sand, Mystery Behind the Wall, and Bus Station Mystery. In Mystery in the Sand, 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?

When an oil spill takes place off the coast of Connecticut, the Aldens are happy to volunteer to help clean up the animals affected, including a rare species of shore bird. But could more have been done to prevent the spill? As the Aldens take up the case, it leads them on an adventure to help other endangered animals around the world.

Three complete stories in one collection! Includes The Mystery Girl, The Mystery Cruise, and The Disappearing Friend Mystery. In The Mystery Girl, Henry, Jessie, Violet, and Benny are working in a general store to help out a friend of Aunt Jane’s. It seems to the children that the young girl who works in the store is behaving very strangely. She seems nervous and won’t answer any questions about her past. Then a strange man comes to the store asking about her. What secret is the mystery girl hiding?