Threshold State (Zac Johnson #1)

Threshold State (Zac Johnson #1) by Dave Bartell is out now (published November 1, 2026).

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Threshold State (Zac Johnson #1)

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Threshold State (Zac Johnson #1) Release Date: November 1, 2026

Published

A man discovers something impossible inside his skull: the neural implant that changed his life has been altered without his knowledge.
Before he can tell anyone what he found, he is dead.
The technology that killed him was supposed to be a miracle.
Neurosurgeon George Walker and a brilliant Silicon Valley engineer have created a new generation of brain-computer implants capable of restoring functions once thought permanently lost. Patients who struggled to speak, remember, hear, or navigate the world are being given their lives back. The results are extraordinary. The possibilities seem limitless.
Then Celine Mendoza comes to Walker with a problem no one can know about.
A rising political star and candidate for Vice President of the United States, Celine is concealing a worsening hearing impairment that could end her career. Desperate for a solution, she agrees to become the secret recipient of Walker’s newest experimental implant—a device far more sophisticated than anything approved for human use.
It works.
Celine can hear again.
Soon, she realizes it has given her something more.
Her memory sharpens. Connections come faster. Complex problems seem simpler. Conversations that once demanded concentration become effortless. She can absorb information with startling speed and see solutions before the people around her have fully understood the problem.
Then her party wins the election.
And when the President-elect dies unexpectedly, Celine Mendoza is suddenly nine weeks away from becoming President of the United States.
She throws herself into building an administration capable of matching the future she can already see. But increasingly, the people around her seem frustratingly slow. When Celine learns that several other influential Americans have received earlier versions of the same technology, she begins drawing them into her new government.
Most people see brilliance.
Secretary of Energy Noreen Davis sees a pattern.
She quietly turns to Zac Johnson, a former Army Ranger and gifted scientist accustomed to problems that don’t fit neatly inside anyone’s jurisdiction. What begins as a discreet inquiry into the company behind Celine’s implant leads Zac to a dead patient, hidden data, altered software—and evidence suggesting the technology may be capable of something its creators never disclosed.
The question is no longer simply what the implant is doing for Celine.
It’s what it may be doing to her.
And whether every thought guiding the next President of the United States is entirely her own.
Before Zac can determine the answer, the engineer responsible for the implant’s most advanced capabilities disappears. He takes with him a secret no government can afford to lose—and the means to reach technology already embedded inside human brains.
Now someone else is looking for him.
As Inauguration Day approaches, Zac’s investigation becomes an international hunt stretching from Silicon Valley and Washington to the foothills of the Himalayas and the streets of Istanbul. Intelligence services circle. A hidden buyer emerges. And the missing engineer realizes that what he possesses may be worth far more than money.
Because controlling the technology could mean something far more consequential than stealing secrets from the incoming President.
It could mean influencing what she believes.
What she decides.
And what she does next.
Zac has only days to find the man who created it and determine how far the technology has already gone.
But the most dangerous question may be one no investigation can answer:
If an idea enters your mind and feels completely like your own, how would you ever know it wasn’t?

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Genre: Thriller

Dave Bartell

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