Every vault hides more than gold.
Beth Tackett was found beaten to death behind the motor pool at Fort Knox. The Army calls it random. Her husband doesn't believe it - six weeks before she died, Beth told him something felt wrong on post.
So Ed builds a machine. Small, silent, built from twenty years of mining instinct and a grief he can't carry any other way. He tunnels toward the most secure building in America, chasing a rumor that's followed Fort Knox for decades: the gold isn't all still there.
He's caught. Publicly humiliated, quietly dismissed as a broken man chasing conspiracy - exactly what the people protecting this secret were counting on.
But what Ed eventually finds isn't buried where anyone expected. And the deeper he digs, the closer he gets to the truth that got his wife killed.
Knox is a thriller about grief that won't take an easy answer, and one man who refuses to stop digging until he finds out what his wife died knowing.