"Hello, here's a dead dog," is how the British Museum's new exhibition greets you. The plaster cast of the void left by the poor animal as its body decayed under piles of volcanic ash, hardened to rock, captures its final, writhing death throes. It's an astonishing thing to be confronted with straight off but captures what you'll see over the next 90 minutes: touching domesticity, all foreshadowed by that looming eruption.
The British Museum has titled it Life and Death in Pompeii and Herculaneum, the two towns buried by Vesuvius in 79AD. But where we always connect these places with horrible death, this exhibition focuses on ordinary day-to-day life. The ash and superheated gases preserved the towns beautifully: in Herculaneum, wood, food and leather instantly carbonised, meaning we can stare at a loaf of bread from 2,000 years ago. It's not even been broken, it must have been baked that day. We were reminded of photos from within Fukushima province, of a kitchen table covered in rotting food left when the inhabitants fled. That was poignant; this Roman loaf unbearably so.
There are lots of these little touches, arranged in the format of a real house from Pompeii, so we get to wander round the atrium, the dining room, the garden and kitchen. Discover the Roman love for fermented mackerel sauce, see the graffiti scratched into stones, imagine using an exquisitely decorated colander and pot for fattening up dormice, or listening to the tinkle of the penis wind chimes.
Frescoes have been prised off the walls so the 'house' is full of art; some delicate, some funny, some rude, some portraits of real Pompeiians where you can look into their eyes and wonder if they were alive when the volcano blew, and whether they ran or whether they're one of the plaster casts.
Ah, the casts. The famous, grisly mementos. The exhibition ends with a few of them. The plaster casts are replicas of the originals, which are too delicate to travel, but the 'Resin Lady' – so called because she is the only mould made of expensive epoxy resin – is the one that was made in situ. You can still see the green marks made by her beads and, ghoulishly, her bones. If you have space, crouch down and look at her face. Her mouth is open. She's probably screaming. They're all screaming.
All too often, blockbuster exhibitions are about kings and generals, people far removed from us. But the beauty and tragedy of Pompeii and Herculaneum is that they were like us. The exhibits don't feel like artefacts, it's just the stuff we all have at home with two differences: 2,000 years and a horrific end. You will never have a better chance to experience ancient Rome.
Life and Death in Pompeii and Herculaneum runs at the British Museum 28 March-29 September 2013. Tickets £15, concessions available. For more information and to book, see the British Museum website. We saw this exhibition as part of the press preview.