Rome, 1508

An abandoned ship is found drifting in the mouth of the Tiber…

When port authorities board the vessel and break open the hatches, they find the bodies of 293 men packed together in the hold – migrant workers shipped over from North Africa, cheap labour to cut the cost of building St Peter’s.

All have died in the most horrendous circumstances.

The Vatican is desperate to distance itself from this atrocity; the traffickers must be found and punished, and the entire illegal trade in people must be stamped out.

The Pope charges his Head of Security, Domenico Falchoni with conducting a full investigation. Domenico turns to his scholar sister Cristina for help, and together they delve into the grudges and rivalries of the old dynastic families who are competing for contracts to build the world’s greatest cathedral.