Scars of Duty by Susie McIver

Boone Grant doesn’t believe in ghosts.
He hunts them.
When a covert handler calls him before dawn with news of a quiet recruitment network forming in the mountains of Montana, Boone knows exactly what it means. Someone is building an invisible army—one loyal operative at a time—and the blueprint looks disturbingly familiar.
Sentinel may be gone…
but his ideas are still alive.
To infiltrate the operation, Boone is forced to work with the one person he swore never to trust again.
Wren McKay.
Years ago, Wren destroyed her career, when she signed Boone’s name to a mission, she rewrote a classified mission, without explanation—taking his heart with her. Boone believed she betrayed him.
Now he’s learning the truth might be far worse.
As they track a silent network recruiting veterans, medics, and specialists who vanish without a trace, Boone and Wren realize the threat isn’t a strike team.
It’s an infrastructure.
A ghost army that could reshape the future of war.
But the deeper they dig, the more dangerous the mission becomes—and the harder it is to ignore the truth between them.
Because the past they buried wasn’t betrayal.
It was sacrifice.
And the scars they carry might be the only thing strong enough to stop what’s coming next.
In a war built on secrets, trust is the most dangerous weapon of all.