Atticus, captain of one of the ships of Rome's small coastal fleet, is from a Greek fishing family. Septimus, legionary commander, reluctantly ordered aboard ship, is from Rome - it could never be an easy alliance. But the arrival of a hostile fleet, more powerful than any Atticus has encountered, forces them to act together. So Atticus becomes involved in a political struggle that is completely foreign to him. Rome urgently needs to build a navy but the obstacles are many: political animosities; legions entrenched in traditional methods; Roman prejudice against perceived outsiders. The enemy is first class, experienced and determined to control the seas. Can Atticus, and the fledgling Roman navy, staffed with inexperienced sailors and unwilling legionaries, outwit and out-fight his opponents?