Secrets of the Tombs Books in Order

Secrets of the Tombs is the Helen Moss series for readers who want their mysteries bigger, older, and a little more dangerous. Instead of one home base, the books move through real archaeological sites around the world. At the center are Ryan Flint and Cleo McNeil, two teenagers who keep finding themselves in the middle of crimes, legends, and ancient puzzles that refuse to stay buried.

These books like real history, but they never feel like homework.

The first book, The Phoenix Code, takes Ryan to Egypt's Valley of the Kings, where he teams up with Cleo and stumbles into secret codes, hidden treasure, and a mystery with roots thousands of years old. The Dragon Path shifts the action to China, where family history, ancient poisons, and terracotta warriors all become part of the danger. The Serpent King heads to Mexico and the Maya city of Calakmul, opening the series out again while keeping the same balance of present-day suspense and older buried stories.

Ryan and Cleo make a good team because neither of them can solve these cases alone. Ryan often arrives as the outsider, seeing how odd things look from the outside. Cleo is more at home around digs, artefacts, and academic adults, but she is just as ready to break rules when the stakes rise. Around them are parents and experts whose work gets the pair close to extraordinary places, even if the adults do not always realize how much trouble is brewing.

What links the books is the way Moss uses the setting. The archaeology is not just backdrop. Tombs, ruins, coded objects, local legends, and old rivalries all shape the case. The danger usually comes from two directions at once: the physical risks of unfamiliar places, and the human risks of greed, secrecy, and people who badly want certain objects or knowledge to stay in their hands. That gives the series a faster, higher-stakes feel than Adventure Island, while still keeping the clue-solving core.

There is plenty of action here, but the books are not only about chase scenes. They are also about curiosity, trust, and what happens when the past still has the power to change the present. Moss clearly enjoys research, and that shows, yet the stories stay readable and brisk.

If you want young detectives, but you also want coded messages, lost relics, dangerous digs, and a strong sense of place, this is probably the best place to go in Helen Moss's backlist. Start with The Phoenix Code and the series builds neatly from there.