The previous post was on a book (in italian). In the fiction, a time-traveler comes back from future in the Rome of 44 BCE, to save Julus Caesar's life. The book is entitled "The Parthian War".
Had Caesar ever been involved in Parthian Wars? Here from Wiki
"In 53 BC, Crassus led an invasion of Mesopotamia, with catastrophic results; at the Battle of Carrhae, the worst Roman defeat since the Battle of Cannae, Crassus and his son, Publius, were defeated and killed by a Parthian army under General Surena. The bulk of his force killed or captured; of 42,000 men, about half died, a quarter made it back to Syria, and the remainder became prisoners of war. The following year, the Parthians launched raids into Syria, and in 51 BC mounted a major invasion led by the crown prince Pacorus and the general Osaces, but their army was caught in an ambush near Antigonea by the Romans under Cassius and Osaces was killed.
During Caesar's civil war
the Parthians made no move, but maintained relations with Pompey. After
his defeat and death, a force under Pacorus came to the aid of the
Pompeian general Caecilius Bassus, who was besieged at Apamea Valley by the Caesarian forces. With the civil war over, Julius Caesar elaborated plans for a campaign against Parthia, but his assassination averted the war. During the ensuing Liberators' civil war, the Parthians actively supported Brutus and Cassius, sending a contingent which fought with them at the Battle of Philippi in 42 BC.
More on http://en.wikipedia.org/wiki/Roman–Parthian_Wars