Henry, Jessie, Violet and Benny Alden, the Boxcar Children, arrive at Camp Seagull, eager to begin a new week of making friends and participating in the annual camp Olympics. But someone is determined that they won't win! Can they find out who before the Olympics is ruined for everyone?

"The Alden children continue their mission to return lost artifacts around the world by visiting the Pyramids in Egypt and Stonehenge in England, among other places, but along the way they must outwit a thief."--Provided by publisher.

The growling bear mystery: The Aldens love exploring the many hiking trails around Yellowstone, especially Lost Cabin Trail. But suddenly, the trail is closed because of bear activity, and then the map disappears! Could someone be trying to keep the Aldens away from the trail? It's a mystery -- and the Boxcar Children are going to solve it! The mystery of the lake monster: When the Aldens arrive at Lake Lucille, they're excited to explore the forests...