This audiobook is narrated by a digital voice.

When his archaeologist father goes missing after an air crash in Mexico, UFO-obsessed Josh Garcia suspects alien abduction. On the Internet Josh soon finds like-minded friends. But after he discovers his dad was murdered, he's propelled into an urgent race to find a lost book of the ancient Maya.

Could the mysterious 'Ix Codex', missing for centuries, contain the secret to surviving a prophecy of apocalyptic doom?

Josh might be the only person alive who can find it - but there are forces out there who'll do anything to make the prophecy come true.

Will Josh survive long enough to unravel the mystery of what happened to his dad?

Invisible City is the first in a 5-part time-travel adventure series for readers who enjoyed tightly-plotted series for children and young adults, like Harry Potter, Percy Jackson and The Maze Runner.

Praise for 'The Joshua Files'

"A splendid adventure story of UFOs, ancient Mayan documents and a lost city. The hero is eminently likeable, there is a splendid only-you-can-save-the-World denouement and you'll come away with a degree of esoteric knowledge about ancient Central America as well." Louisa Young, 23 March 2008, Mail on Sunday

"A gripping survival story begins...a boy's fantasy of pyramids, caves and tunnels. Josh's quest for a long-lost Mayan text giving the key to salvation is bound up with his personal destiny in an unexpected way. But he is also, like all 13-year-olds, uncertain of what the future will bring. Harris cleverly captures this pivotal period." Carole Mansur, 15 March 2008, The Telegraph