In reading order
The Secret Explorers and the Lost Whales
SJ King
The Secret Explorers and the Comet Collision
SJ King
The Secret Explorers and the Tomb Robbers
SJ King
The Secret Explorers and the Jurassic Rescue
SJ King
The Secret Explorers and the Rainforest Rangers
SJ King
The Secret Explorers and the Smoking Volcano
DK
The Secret Explorers and the Missing Scientist
SJ King
The Secret Explorers and the Plant Poachers
SJ King
The Secret Explorers and the Moon Mission
SJ King
The Secret Explorers and the Haunted Castle
SJ King
The Secret Explorers and the Ice Age Adventure
SJ King
The Secret Explorers and the Desert Disappearance
SJ King
The Secret Explorers and the Sunken Treasure
SJ King
The Secret Explorers and the Cave Crisis
SJ King