Kimball Hayden is the commander of an elite commando group known as the Vatican Knights, a black-op force that works for the Church to protect its sovereignty, its interests, and the welfare of its citizenry. But Kimball is being stalked by someone from the past, a soldier who is stronger, faster, and far more brutal - an assassin so deadly not even the Vatican Knights can stop him.

While vacationing in Paris, Shari Cohen's children are kidnapped by Jadran Božanović, a Croatian kingpin who runs a human-trafficking cartel and is as deadly as the knife he wields. Few dare to challenge him. And even fewer dare to defy him. With time running out and her resources running thin, Shari calls upon the aid of Kimball Hayden and his team Vatican Knights - an elite group of commandos dedicated to protect the sovereignty, interests, and citizenry of the Church - and are once again reunited.

Long before Kimball Hayden became a Vatican Knight, he once served as an elite assassin for the US government. After the ordered assassination on a United States senator by a cabal within the US command, Kimball is set up for failure and is believed dead by the Pentagon brass. But when a leading political principal involved with the senator's murder discovers that Hayden is alive, he's immediately seen as a threat to a certain few on Capitol Hill regarding the sanctioned hit on the senator, and those involved.

Growing up with a sheltering mother and a belligerent father, Kimball Hayden's young life goes from one of innocence to the depths of chaos. When a vicious syndicate of murderers and extortionists begin to run the streets, Kimball soon becomes the focal point of their attention. His family is placed within the crosshairs, friends go missing or are found dead, all messages from the Gangster Prince. But when Kimball's world shatters and he grieves a great loss, the sleeping giant within him awakens.

In an abandoned church deep inside the Syrian Desert, Father Jenkins watches over a group of children who'd been orphaned by war and unrest. Having been marked for extraction by the Vatican Knights, a cabal of ruthless killers from the Islamic State cripples all attempts of safe passage and gives chase across a desert landscape that's completely ruled by scorpions and snakes.

After the march on the Vatican by the Islamic State, the radical group begins its push deeper into the European and American Fronts. But when the True Cross - the wooden remnants of the cross Jesus was crucified upon and the holiest of all relics - is stolen from the Church of the Holy Sepulchre by the Islamic State, it becomes clear that the relic is to be bartered to an arms dealer for weapons so devastating that Europe and the United States could be rocked to their very foundations.

In Washington, D.C., three priests have been murdered and mutilated with their corpses hanging upside-down in mock crucifixion. The only indicator as to the culprit is a 500-year-old order known as the Nocturnal Saints, an underground faction that had been borne from the Protestant Reformation and acts as judge, jury, and executioner against those deemed to be in contradiction of old-time traditions. So when Special Agent Shari Cohen of the FBI is called to track down this faceless enemy, she’s joined by the Vatican Knights, who have been dispatched by the pontiff to counteract the order.  

When a cardinal is taken captive by an ISIS faction in Damascus, a team of Vatican Knights is dispatched to secure the cardinal's release. But having been ambushed and taken hostage themselves, only one man can bring them out. After Kimball Hayden walked away from the church months before, he is summarily called to duty by Vatican principals to rescue his team. But as Kimball works in the Dark to serve the Light, he discovers the truth behind the ambush and follows the trail of the betraying source directly to the Vatican. 

In Geneva, a highly valued product with the power to cause major destruction is stolen from the CERN. Eighty kilometers from the Austrian border, a young girl becomes the key that controls the will of the man with the power to create and destroy. In the mountainous regions of Switzerland, a hostile force from a pariah regime attempts to extract a scientist from a fast-moving train.

After a sacred tome written by the hand of Saint Peter is stolen from the Vatican’s Secret Archives, people around the world begin to die at the hands of a madman once the secrets of The Brimstone Diaries are unveiled. In Rome, a terrorist faction has quietly breached the ranks of the Vatican hierarchy. As the conspiracy within the ranks begin to materialize, the greatest threat to the Vatican State is about to commence with Vatican City caught dead-center within the crosshairs of total annihilation.

In Southeast Turkey, where the heads of the four main rivers once met, a magnificent temple created 14,000 years ago is discovered beneath the desert floor. Believed to have been created by lost technology, it is quickly determined by a team of archeologists to be the centerpiece of Eden, a once illustrious civilization and the cradle of mankind. But what if Eden is not the paradise that the texts make it out to be? What if it held dark secrets and unholy terrors instead?

While on a mission in Jarablus, Syria, Jon Jericho, codename the Hunter, is severely wounded, ending his career as a Special Field Operative for Delta Force. When he returns stateside to begin life anew, he quickly finds himself caught up in a scandal involving the appropriation of documents for an undetectable state-of-the-art ICBM by the Islamic State. But what if Jon Jericho discovers something different?

Nearly 65 million years ago an asteroid collided with the Yucatan Peninsula in the fifth and final extinction event that nearly destroyed all life on Earth. But when a recent earthquake exposes something unusual 2,000 feet beneath the Yucatan Peninsula, cryptanalysts Alyssa Moore and John Savage are called in to investigate this peculiar structure that bears uncanny resemblances to writings discovered in Eden.

During military exercises, rogue missiles fire off from a US naval battleship and head directly towards North Korea. Then Air Force Two disappears over the Rocky Mountains. These are mere flexes of muscle from one man who wields the Black Key, a tool capable of controlling nuclear arsenals and weaponry systems. President Jack Meacham's past comes back to haunt him with a single message: "Are you willing to sacrifice your life for the good of the whole?" The president turns to Jon Jericho, a.k.a. The Hunter, to locate and neutralize the man behind the Black Key.

Even when ex-SAS major Ben Hope is taking a holiday, trouble seems to find him. What started as a relaxing trip to the Deep South spirals into a nightmare when he’s wrongly accused of a vicious murder and forced to go on the run. Target of a state-wide manhunt, the only way Ben can prove his innocence is to unearth a long-forgotten secret and track down the killers who slaughtered an innocent woman in a vendetta dating back generations. His quest takes him into the wild heart of Louisiana’s swampland, where all hell’s about to break loose.