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。

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。

Complete your collection with:

The Nebula Secret （1）
The Falcon’s Feather （2）
The Double Helix （3）
The Star Dunes （4）
The Tiger’s Nest （5）
Explorer Academy Code-Breaking Adventure
Explorer Academy Ultimate Activity Challenge
Explorer Academy Field Journal
Explorer Academy Future Tech