While in Machu Picchu, Peru, with their parents, eight-year-old twins Ethan and Ella cross a secret bridge and discover a mysterious stone sculpt

With help from their cousin Harry, eight-year-old twins Ella and Ethan discover who is illegally taking coral from the reefs near their aunt and

"While visiting Alaska, Ethan and Ella follow some icy paw prints that lead to a brand-new mystery"--

In Venice, Italy, second graders Ethan and Ella hope to find a stolen gondola and a hidden mosaic before their parents realize they are missing.

"In Paris, France, twins Ethan and Ella must find a stolen painting and a secret bakery without giving themselves away"--

The mystery of the gold coin: Second graders Ethan and Ella are sad about moving away from their hometown to travel the world with their mom, a j

"Twins Ethan and Ella go on an adventure in Greece, where they learn about the mystery-solving Society of Apollo"--

"Twins Ethan and Ella are in the Maasai Mara in Kenya, and there's another mystery to solve. Where are all the lions? Ethan and Ella spot lots of