A legendary angel. A modern madman. A mission that could unleash the armies of Heaven.

As Master of the Order of Thaddeus and a former Army Ranger, Silas Grey has faced ancient threats and modern enemies alike. But nothing prepares him for the chaos that erupts after a shocking assassination attempt hits close to home—followed by the sudden disappearance of two elite agents investigating a mysterious case tied to a growing spiritual danger.

Something sinister is brewing. Sacred relics are vanishing. Classified research is stolen in coordinated break-ins. And whispers of supernatural warfare echo from the trenches of history—pointing to a spectral force and forgotten legends someone intends to harness.

A plan is unfolding to weaponize divine power and ignite a bold invasion—one that threatens to upend the global order.

Drawn into a rising conflict with cosmic consequences, Silas and his SEPIO team must race to uncover ancient secrets and confront weaponized celestial forces before the world spirals into chaos.

Can the Order unravel the latest conspiracy before Heaven's armies fall into the wrong hands?

The Guardian Exchange is the fourteenth gripping installment by bestselling author J. A. Bouma, an explosive blend of spiritual suspense, historical mystery, and geopolitical thrills. Perfect for fans of James Rollins, Steve Berry, and Dan Brown, SEPIO's latest mission delivers a powerful mix of faith and fact in a race to stop an unholy war.

Join the newest gripping adventure in the bestselling series readers call "a thrilling ride full of action, faith, and historical depth"—delivering suspense, mystery, and meaning in every page-turning twist.