The Boundless by Kenneth Oppel
Three years pass, and Will is aboard The Boundless, the longest steam train ever, with 987 cars, stretching more than 7 miles. Suddenly and unexpectedly, Will becomes the protector of a secret key that unlocks endless treasures and riches. Murder, villains, creatures, and more keep this heart pounding, thrilling adventure steaming forward. Working with the young escape artist, Maren, and the mysterious ringmaster, Mr. Dorian, Will must save himself, his father, and The Boundless.
Historical fiction mixed with fantasy and adventure makes this book an exhilarating read. I could not put this book down, and I needed to know what happened next to young Will, daring Maren, and the strange Mr. Dorian. A great middle grade read! Hop on board and hang on tight because it is a gripping ride!