Acre, 1291. The last Crusader city in the Holy Land is about to fall. Two Knights Templar, obeying the grandmaster’s orders, manage to escape the invading Muslim army on the order’s last ship. New York City, nowadays. During the unveiling of an exhibition of some of the Vatican’s treasures, four men disguised as Templars attack the Metropolitan Museum and steal several artefacts, including a centuries-old decoder – a loss that horrifies the Church.

The investigation onto the museum raid continues, but it’s a difficult one. One of the four ‘knights’ has already died in his – guarded – hospital room, and FBI Agent Reilly is unknowingly engaged in a race to find the other thieves before the mysterious assassins trying to eliminate them. Meanwhile, young archaeologist Tess Chaykin is following up the Templar lead – one that the FBI considers too far-fetched to be worth looking into...

After being kidnapped by Vance and subsequently escaping, Tess is now officially part of the investigative team alongside Agent Reilly. But despite the constant danger of the lurking assassins who have already nearly killed her once, the young woman refuses to play a passive role. Her research will take her far from New York, under the protection of Sean Reilly – who is about to face a terrible crisis of faith.

Tess has gone with Vance to look for the Falcon Temple and its precious cargo, convinced that truth must prevail. Meanwhile, the Church persuades Sean to help them keep that truth hidden – at any cost. On the dark waters of the Mediterranean, in a storm so fierce it could be the very wrath of God, a merciless battle will take place for the future of the Christian faith...

1203. Constantinople is besieged ... by the Christians of the 4th Crusade! Under cover of night, a small group of knights flees the doomed city. They’re taking three mysterious chests to Antioch – but never reach their destination. Nowadays, in Rome, Agent Reilly has come with a Professor Sharafi to request access to the Vatican’s archives. But once inside, he reveals that the document they’re here to consult is one that the Church doesn’t want anyone to see...

Reilly has tracked down the fake Professor Sharafi to Turkey. But the man is crafty, and not only does he manage to escape, he also recaptures Tess along the way. A chase begins across the hills of Cappadocia, with the FBI agent hunting down his enemy while Tess, in order to survive, does her best to follow the trail of Knight Templar Conrad and the mysterious treasure he was protecting – the one everyone thought was a threat to all of Christianity...