Benny and his friend Mike are in trouble when they are curious about a uranium mine.
The Aldens find a castaway on a South Sea island. How did he get there and who is he?
A double puzzle involves an old friend of Aunt Jane's, romance, and a chase.
15) Bicycle mystery
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!
28) The mystery girl
Someone steals the newly refurbished boxcar the Aldens are going to ride at the Greenfield Founder's Day Parade, they only have a couple of days to find it before the event.
The Alden children are going back in time by helping at an old Victorian house that has been turned into a museum. But rumor has it that the place is haunted by the spirit of practical joker Horace Wagner! Is there really a ghost?
The Aldens are helping to map out a new trail on Blizzard Mountain. As they travel through the frozen wilderness, they learn that there's treasure buried somewhere on the mountain! The children begin to search for it, but someone or something is after them. Is Blizzard Mountain haunted, or is someone after the treasure?
When their friend Sam gets a letter full of riddles from an eccentric millionaire, the Aldens are eager to help him crack the code. If Sam can solve the puzzle, he will inherit the millionaire's money! But Sam isn't the only one in town to receive a letter - and whoever solves the mystery first will win the prize!
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!