Down there, beyond the deepest caves, below the crust and the mantle, there is another world. An old woman locked away in a Russian asylum has a secret - knowledge of a 500-year-old manuscript written by a long-dead alchemist that will show a passage to the mythical centre of the Earth. She knows it’s real because 50 years ago, she and a team travelled there. And only she made it back. Today, caving specialist Mike Monroe leads a crew into the world’s deepest cave in the former Soviet Union. 

Pompeii, present day: archaeologist Maria Monti is working at a new dig site. Like hundreds before her she is investigating the night that Vesuvius erupted, consuming the ancient city with choking ash, scalding steam, and rivers of lava. But she has just unearthed something that shouldn’t be there, something that makes her question everything she knows about the disappearances of that fateful event. Several hundred miles away Alex Hunter’s family is holidaying in southern Italy when Mount Etna begins to shake, and ash begins to blanket the countryside....

The Arcadian returns to the dark ice in a reprisal of one of his first and most deadly missions. But this time the stakes couldn’t be higher. In 2008, a top-secret US submarine went missing on its test voyage off the coast of Antarctica. After years silent, its emergency beacon is suddenly activated, but strangely, the beacon is emanating from a point miles below the ice sheets of the frozen continent. The race is on.

The sequel to the number one Audible Best Seller Earthcore, Mount Fitz Roy continues the tale of Patrick O’Doyle and Bertha Lybrand, who were part of the horror show that occurred far below the mountains of Utah. They learn that the "mother of all motherlodes” discovered there was not unique, that there is another deposit similar to it three miles beneath the towering peak of Cerro Chaltén on the disputed border between Chile and Argentina. O'Doyle, a middle-aged former member of a disgraced black-ops unit, gets his aging team back together to go after this fortune.

Something has travelled for a billion years to find us - and now it has. In space, Commander Mitch Granger and his crew are nearing the end of their scientific mission - along with their covert satellite photography for the military. As they prepare for reentry, an unknown object emerges from the void: the name given to deep, dark space. The object proves impossible to evade. The crew have one option left - to bring the fragment aboard....

Massive sinkholes are opening across the country – each larger and deeper than the previous one. First the family pets go missing, and anyone living near one of the pits, is reporting strange phenomena – the vibrations, sulphurous odours and strange sounds rising up from the stygian depths. Then come the reports of horrifying ‘things’ rising from the darkness.When the people start disappearing the government is forced to act.

An ancient evil awakens ... Alex Hunter has been found – sullen, alone, leaving a path of destruction as he wanders across America. Only the foolish get in the way of the drifter wandering the streets late at night. Across the world, something has been released by a treasure hunter in a hidden chamber of the Basilica Cisterns in Istanbul. Something hidden there by Emperor Constantine himself, and deemed by him too horrifying and dangerous to ever be set free.

In a Mexican temple, archaeologists uncover the remains of a half-human hybrid. They believe it is related to the creature in Antarctica, a dark thing of legend that is still alive-and still evolving. They believe it needs a new host to feed, to mutate, to multiply. They're right. And they're next. And the human race might just be headed for extinction.

Lawless, British Columbia is on edge after a powerful earthquake jolts the region, quickly followed by a string of savage animal attacks. Newly stationed to the area after her predecessor mysteriously disappears, Conservation Officer Christine Moon needs to calm the jangled nerves of the small mountain town. Awakened from ancient slumber, something stalks the swirling, grey mists that surround Lawless. A beast with a gnawing hunger that grows stronger by the minute - its only thought, to satisfy its ravenous appetite.

EarthCore is the company with the technology, the resources, and the guts to go after the mother lode. Young executive Connell Kirkland is the company's driving force, pushing himself and those around him to uncover the massive treasure. But at three miles below the surface, where the rocks are so hot they burn bare skin, something has been waiting for centuries. Waiting...and guarding. Kirkland and EarthCore are about to find out first-hand why this treasure has never been unearthed.

A sudden burst of radiation is detected beneath the desert in Iran. Alex Hunter – code name Arcadian – and his highly trained incursion team are dropped into the ruins of Persepolis. All they find is an empty underground facility – nothing to explain the gamma spike. It is as if a black hole has swept everything away.... Israel is threatening nuclear war. And someone, or something, is draining the fluids from the bodies of Iranian soldiers in the desert.

Alex Hunter, code named Arcadian, wakes up with no knowledge of who he is, in the care of a woman he doesn't recognize, in a country not his own. But there is a calling deep within him, to return home to Black Mountain. Formed a billion years ago, the Appalachian's Black Mountain hosts a terrible legend. Only one elder remains to guard its long-forgotten, deadly secret and there is a fear that there is evil lurking again. Some hikers have gone missing, and the rescue team sent to search for them has not returned.

In December 2018, Ben Cartwright, former Special Forces soldier, and a team of naive explorers followed the clues left by his ancestor to a hidden plateau in the middle of the Amazon jungle. It was said that once every 10 years, a secret pathway was revealed to a world long since gone. They went, and what they found was a place of wonders and of horrors. Only Ben and his childhood love, Emma, survived. But when the doorway to the hidden world closed, Ben was trapped on the wrong side. Now, Emma has waited 10 long years for the doorway to open again. This time she’d be ready. 

A journey into the deepest, darkest jungles of the Venezuelan Amazon...and a primeval place and time that mankind was never meant to exist in. Ben Cartwright, former soldier, home to mourn the loss of his father, stumbles upon cryptic letters from the past between author Arthur Conan Doyle and his great-great-grandfather who vanished while exploring the Amazon jungle in 1908. Amazingly, these letters lead Ben to believe that his ancestor’s expedition was the basis for Doyle’s fantastical tale of a lost world inhabited by long-extinct creatures. 

Deep in the steaming jungles of Paraguay, Aimee Weir is in trouble. The petrobiologist has found what she was looking for - a unique microorganism in a natural gas deposit - but it proves to be more destructive than anyone could have imagined. A contagion is striking down all in its wake. The camp is quarantined, but workers start to vanish in the night. Is it fear of contamination - or has something far more lethal come to the surface? Something that has been trapped beneath the miles of stone, waiting... for us.