Cruz, Sailor, Emmett, and the gang are on their way to Africa when Nebula misses their intended target and someone close to Cruz ends up on the brink of death. Secrets creep out from the shadows and leave Cruz with more questions than answers in this fourth title in the hit series.

A major discovery forces the Explorer Academy into the limelight in The Star Dunes, but Cruz has much more on his mind than 15 minutes of fame. A new face on board the ship brings Cruz's worlds colliding, just as a major close call tears them apart. En route to Africa, Team Cousteau is now down a major player, and Cruz can't help but be preoccupied by the hole in his life. The discovery of his mom's next clue leads him to the most exotic location yet--a vast desert--with no other information to lead the way, while an unlikely ally helps Cruz pursue another piece of the puzzle. Just as things seem like they might turn out alright, Dr. Fanchon Quills has a technological breakthrough which gives Cruz a glimpse into the past and reveals more about his future than he may really want to know.

They waddled into stardom in National Geographic’s March of the Penguins film. These guys are now nature’s ROCK STARS! If you’re age 5, you’re probably as tall as an Emperor. But why do they throw up so much? March this way, and find out all!

National Geographic supports K-12 educators with ELA Common Core Resources.

Visit www.natgeoed.org/commoncore for more information.

It's an adventure of a lifetime when Cruz Coronado sets sail for the shores of Iceland and Norway aboard the Explorer Academy ship to continue his studies at sea. But, things take a turn while exploring the icy north, when he embarks on a dangerous mission to uncover the first piece of an important puzzle his mother left behind.

In the exciting follow-up to The Nebula Secret in the 7-book Explorer Academy series, Cruz, Sailor, and Emmett, along with their new ally Bryndis, embark on their first globe-trotting mission aboard the ship Orion. Cruz jumps right back into school and starts using the latest technology in submersible underwater dives, but is soon reminded of the dangers of exploration when his equipment fails and he almost drowns. Determined to keep his eyes on the prize, Cruz sneaks away to try to find answers, but unknowingly lures his friends into bigger trouble. When a friend of Cruz's mom meets an untimely end, Cruz's luck really seems about to run out and the questions multiply. What does the message mean? Where will it lead? Who is following him? And why?

This captivating book is the sequel every Explorer Academy fan is waiting to read!

The mystery deepens and the action intensifies for 12-year-old Cruz Coronado and friends in the exciting third book in the Explorer Academy series.

The adventure continues for Cruz, Emmett, Sailor, and Bryndis as they continue their studies at sea and travel to exotic locations around the world. A mysterious person alerts Cruz to impending danger while he and a few trusted pals explore ancient ruins in Petra, Jordan, and search for another piece of the puzzle his mother left behind. Worst of all, now his father has gone missing, which prompts Aunt Marisol, his number one protector, to leave the ship in search of him. Who is the new professor who takes her place? How does the new technology he introduces help or hurt Cruz's quest? Why is Nebula determined to stop Cruz before he turns 13? The clock is ticking as his first teen birthday draws near ... a milestone that will change his life forever, one way or another.

Adventure, danger, and a thrilling global mission await 12-year-old Cruz Coronado as he joins an elite school for explorers.

Cruz leaves his tranquil home in Hawaii to join 23 talented kids from around the globe to train at the Explorer Academy with the world's leading scientists to become the next generation of great explorers. But for Cruz, there's more at stake. No sooner has he arrived at the Academy than he discovers that his family has a mysterious past with the organization that could jeopardize his future. In the midst of codebreaking and cool classes, new friends and augmented reality expeditions, Cruz must tackle the biggest question of all: Who is out to get him, and why?

Readers can get in on the excitement with puzzles and codes embedded throughout.