NOW IN PAPERBACK: An explosive revelation and a familiar face heighten the mystery for Cruz and friends in the sixth book in this adventure-packed series.

Still reeling from the life-changing discovery he found buried in the mysterious Archive, Cruz Coronado grapples with an important secret as the gang heads to China in search of the second-to-last piece of the cipher. Under the watchful eye of a new adviser, life on the ship returns to almost normal ... almost.

Just as things seem to be going smoothly, a familiar face shocks Cruz back into reality, and the final piece in this life-and-death scavenger hunt veers toward a dead end.

The paperback edition includes the same great content and back matter as the original hardcover.

Explorer Academy features: Gripping fact-based fiction plot that inspires curiosity with new technology and innovations; amazing inventions and gadgets; a cast of diverse, relatable characters; secret clues, codes, and ciphers to track down within the text; vibrant illustrations; elements of STEAM; National Geographic explorer profiles in the Truth Behind section