Cherry-picking from other movies in the genre seems to be in vogue now (see Oblivion and Last Days On Mars) and while Pompeii freely yoinks bits and pieces from Conan the Barbarian, Spartacus, Gladiator and The Horse Whisperer (that's right) it is essentially Titanic.
After witnessing his family and entire Celtic tribe wiped out by Kiefer Sutherland's none-more-evil Roman general Corvus, northern savage Milo (Harington) is taken south to London to be trained as a gladiator, where his reputation grows quickly over the years. Taken to Pompeii to impress Corvus, now a senator and in the city to oversee Rome's investment in its remodelling, Milo also impresses Severus's (Harris) daughter Cassia (Browning) with his humane treatment of her injured horse. However, nearby Mount Vesuvius grumbles and begins to cough billows of smoke into the air...
So we have noble man of poor birth who is looked down on by the well-to-do. After coming to the aid of a princess, she is swept off her feet despite the gulf between their classes. But romance is a no go as she is being forced to marry a real bad egg to ensure her family's future. As an unforeseen tragedy engulfs all, noble man must rescue the princess while bad egg and his henchman hunt them down. Is that not Titanic?
In Anderson's defence he doesn't keep us waiting as long as James Cameron did before unleashing hell. But maybe he should have as it would have given more time to develop the love story, the backbone of the movie; this is so perfunctory, so story-by-numbers, that there's zero chance of caring one way or another. The only relationship that's given any kind of depth is the friendship between Harington and the dependable Adewele Akinnuoye-Agbaje, a seasoned gladiator but even that's familiar.
They're not helped by the dialogue, with characters reduced to the bare minimum of characterisation.
Sutherland: 'I am a bad man.'
Harington: 'Honour and revenge.'
Adewele Akinnuoye-Agbaje: 'Honour and freedom.'
Browning: 'Help.'
But Anderson's biggest sin is in the botching of the eruption and the chaos that unfolded. This is why we're here after all, but we might as well be observing an ITV documentary from another room for all the emotional involvement it has.