This book is subtitiled Hannibal and the Darkest Hour of the Roman Republic. It is built around the battle of Cannae, Rome’s greatest defeat. It follows Hannibal to the battle, and then follows the ‘ghosts’ of the battle for the rest of the war and even beyond.
At the start of the Second Punic War, Hannibal led an army into Italy and inflicted defeats at the River Trebia, and again at Lake Trasimene. For a year Fabius Maximus, the “Delayer” avoided defeat by avoiding battle.
This didn’t suit the Roman character well, and in 216 BC they decided to create the largest Roman army ever formed, some 80000 men, to eliminate Hannibal.
At the end of the day at Cannae, 60000 or more of these men were dead, Rome’s allies in the area were defecting to Hannibal, and few doubted that the war would end.
Nobody told the Romans, though. Showing how different they were from other nations, even this disaster did not make them give up. The survivors of the battle were exiled to Sicily, never to be disbanded or allowed to return home. They went back to avoiding battle and managed to subdue the defecting cities under Hannibal’s nose, and took away his base in Spain. The war began to turn in their favor.
By 204 BC, Scipio Africanus was ready to invade Africa himself, and used the Ghosts in Sicily as the core of his new army. Hannibal was still in Italy, but after Scipio was camped before the city of Carthage he was recalled to face Scipio.
At Zama, in 202 BC Scipio and his ghosts defeated Hannibal at Zama, ending Carthage as a threat for good. For this, they were finally allowed to go home after fifteen years of exile.