The Bloodline of the Grail: The Last Templar’s Oath releases October 7, 2026
What would you sacrifice to protect something that powerful men would do anything to possess? Your name? Your freedom? And what happens when keeping that promise puts the people you love in danger?
On October 7, 2026, I invite you into a world of hunted knights, concealed identities, and loyalties tested in The Bloodline of the Grail: The Last Templar’s Oath, written under my pen name, Nathaniel Theos. This is the first book in The Last Templar’s Oath series, and it begins with an order that changes one man’s life forever.
The Order may fall. The oath must not.
France, 1307. As the destruction of the Knights Templar closes in, Grand Master Jacques de Molay entrusts Sir Matthieu de Montrose with the Holy Grail. His command leaves little room for misunderstanding: escape, keep it hidden, and protect it from those who would turn the sacred into an instrument of power.
Matthieu leaves Paris with the Grail concealed beneath the boards of a wagon. The knight must learn to pass as an ordinary merchant, watching his words, his movements, even the marks on his hands. One careless answer could betray everything.
But escape is only the beginning. In Portugal, near Tomar, he begins building a life that might conceal his extraordinary burden. An estate needs workers. A household needs trust. And the arrival of Lady Isabeau de Molay brings a connection to the world he left behind, along with questions he cannot easily answer.
As affection deepens and the estate grows, so does the danger. Prosperity attracts attention. Polite visitors ask uncomfortable questions. Men with influence take an interest in things Matthieu cannot afford to explain. The life that gives him somewhere to hide also gives him people he cannot bear to lose.
Seven centuries later, someone is still guarding the silence
In St. John’s, Newfoundland, in 2026, researcher Clara Juliette Moreau discovers a recurring symbol in documents that should have little connection: a French Templar scroll, a Portuguese estate ledger, and a Newfoundland church inventory.
A name keeps appearing. Montrose.
Then a message arrives on her phone: “Stop looking for Montrose.”
For readers who enjoy historical adventure, Templar mysteries, and family secrets, this opening volume brings together the suspense of a forbidden discovery and the intimate story of a man learning what his oath will demand of him. Faith, love, and conscience become practical questions when another person’s safety depends on the choice you make next.
A glimpse inside the book
The following passage comes directly from “The Road South”:
I dared not seek a crowded inn, not with the Grail hidden beneath my wagon and the road behind me still warm with pursuit. Instead, I turned off before sunset and found a stand of trees beyond a low rise, far enough from the road that no casual eye would mark me, yet not so deep that I could not hear anyone approaching. I fed and rubbed down the horse, checked the lashings twice, then knelt beside the wagon and laid my hand beneath it where the hidden weight rested.
I do not know what I expected to feel.
Cold, perhaps. Or nothing.
Instead, I felt a stillness so profound that it unsettled me more than fear. The Grail seemed almost to wait. Not like an object. Not like gold or stone. Like something holy and patient, content to remain veiled until God Himself required otherwise.
Your invitation to the beginning
Many of you know my writing as L. Neil Thrussell. As Nathaniel Theos, I’m taking you into historical adventure, where questions of courage, purpose, and conscience unfold amid dangerous secrets and the ambitions of powerful men. This novel blends historical settings and figures with fiction, imagining a hidden story beyond the official record.
Mark October 7, 2026, on your calendar for the release of The Bloodline of the Grail: The Last Templar’s Oath.
Come meet the man entrusted with the Grail, the people who give him a reason to hope, and the researcher whose curiosity may uncover far more than she intended.
Nathaniel Theos
Also known around the house as Neil.
Book description
To keep the Holy Grail safe, a knight must build a life no one will think to search.
France, 1307. As the Knights Templar face destruction, Sir Matthieu de Montrose receives a final command from Grand Master Jacques de Molay: take the Grail, disappear, and keep it beyond the reach of those who would use it to control the faithful.
With the relic hidden beneath a merchant’s wagon, Matthieu flees toward Portugal. Near Tomar, a neglected estate offers a possible refuge. But land must be worked, neighbours must be answered, and a man with something to hide cannot afford to become interesting.
Then Lady Isabeau de Molay arrives, carrying an unspoken purpose and a connection to everything he has lost. As Matthieu builds a household and discovers the possibility of love, protecting the Grail becomes inseparable from protecting the people around him. Every new bond gives him strength. Every new bond gives his enemies something to threaten.
Seven centuries later, in Newfoundland, researcher Clara Juliette Moreau finds the Montrose name threaded through scattered records. Before she can understand what connects them, an anonymous warning tells her to stop looking.
An oath has survived the fall of an order. What will it demand of the family that inherits it?
The Bloodline of the Grail opens The Last Templar’s Oath, a historical adventure series by Nathaniel Theos, blending Templar intrigue, faith, and the dangerous obligations of a hidden legacy.
