A US Marine named Travis McKinney is sent back in time by a mischievous immortal being named Marty, who is utterly bored by immortality, and whose only form of entertainment is to rewrite history by sending people back in time, to give him new stories to watch, thus giving him something to do. Marty sends Travis McKinney back to 59 BC to play his 'game'. His goal is to have Travis save Julius Caesar from assassination, so he can see how history will then unravel. But there's just one problem - Travis has no idea who that is. However, Marty finds Travis' lack of historical knowledge hilarious, and decides to send him in blind, with no idea about the new world he has stumbled into. Travis quickly finds himself enslaved until his fortunes change drastically. He meets Atia, Caesar's niece, and the two swiftly fall for one another after she buys him at an auction. But for them to be together he can't be a slave; he has to become an aristocrat. Atia then devises a plan to conjure a fake identity for Travis, declaring him as a 'new man' from Hispania. She comes up with the name Titus, and he invents the surname, Maximus, due to his love of Russell Crowe's performance in Gladiator. And with that, Titus Maximus is born.
Travis soon meets the likes of famous figures such as Cicero, Pompey Magnus, Brutus and more. And when he's introduced to Caesar, in order to impress, Travis decides to do what he did best as a teenager. Lie. He somehow manages to impress Caesar enough to gain his blessing to marry Atia, as Caesar is a calculating, shrewd individual who sees something potentially useful in Travis. Then all is well in the life of 'Titus Maximus' as he is wed, while he's also rising high within the Roman aristocracy.
But then, Travis is faced with a major problem. If someone discovers his true identity, that he is actually a slave and not an aristocrat, he learns that he will likely be crucified, and Atia will be shamed. Unfortunately, one man does eventually discover Travis' true identity. And what follows is a battle for family, romance, buddies, and ultimately, survival.
For, as Travis quickly learns, 'when in Rome, do as the Romans do.'