Tomb raider: enter the British Museum's underground mummy store

From Edgar Allan Poe to Scooby Doo, culture is cursed with the ancient Egyptian dead. Jonathan Jones visits the British Museum's mummy store to unwrap our fascination
CT scan 3D visualisation of the mummified remains of Tayesmutengebtiu
Living for ever … a CT scan 3D visualisation of the mummified remains of Tayesmutengebtiu, also called Tamut (detail). Photograph: Trustees of the British Museum Trustees of the British Museum/PR

It was a couple of days after I visited the mummy store that my nightmares began. Bandaged bodies on shelves. A loose wrapping, perhaps about to uncoil further as the corpse within awoke from its 3,000-year sleep. Most of all, the painted face of a young man gazing untiringly into darkness as the curator turned out the lights behind us and firmly locked the door.

Hidden in the heart of the British Museum, deep within a labyrinth of research departments the public never sees, is a secret world of the dead. This museum, whose collections blossomed in the age of empire when Egypt was under British control, owns more than 100 mummies. Many are on permanent display. Eight were taken to hospital to undergo CT scans for the museum's revelatory new exhibition Ancient Lives. Others lie here, on wooden pallets, layered one over the other, in London's most enigmatic morgue.

The room doesn't need to be especially cold – the mummies were embalmed millennia ago, their brains and organs removed to prevent internal decay – but it does have a carefully regulated temperature that suits the fragile dead. Their casings, too, are organic and need care: linen wrappings, wooden coffins. One of the coffins dates from about 3,000BC – older than the pyramids – and is just a timber crate. Later ones are painted in styles from Old Kingdom to Roman, laden with hieroglyphic spells.

Why are mummies spooky? Why are horror stories told about them and why do Scooby Doo scenarios come to mind when you see them in a museum? I'd love to pretend that I was too interested in proper archaeology to waste time on such stuff, but I really did have nightmares after visiting the mummy store. And they got me thinking about what mummies really are: vehicles of immortality.

It's amazing that any Egyptian mummies have survived to be preserved in the British Museum. Over the centuries, thousands have been destroyed through superstition and morbid curiosity. In the 18th century, "mummy", the powdered flesh and bone of the ancient Egyptian dead, was swallowed as medicine. Even when a growing fascination with Egypt made this seem wasteful, things got little better, for public unwrappings of mummies became all the rage. Invaluable archaeological evidence was destroyed for cheap thrills.

Then the horror stories began. The 19th-century writers Theophile Gautier, Edgar Allan Poe and Bram Stoker all wrote eerie tales about mummies, but it was Arthur Conan Doyle, creator of Sherlock Holmes, who hit on the perfect formula of the revived mummy in his story Lot 249. Soon the 1932 Boris Karloff classic The Mummy launched the pharaonic dead on their fantastic film career.

Is all this a depressing insight into our vulgar souls and inability to be interested in the remote past unless it is turned into cheap fiction? No. The gothic imagination feasts on mummies for a good reason. They are genuinely uncanny: the closest that humanity has come to conquering death.

Cartonnage of a priestess, named Tayesmutengebtiu, found in Thebes, 22nd Dynasty. Photograph: Trustees of the British Museumy.

Ancient Egyptians wanted to live for ever. Almost all the Egyptian art and artefacts in museums are part of an effort to achieve this. False doors from tombs – the British Museum has a majestic one painted red that resembles a massive stone Mark Rothko painting – are portals through which the ka, or spirit double, of the deceased person could come to receive food offerings. The models of people brewing beer that were put in tombs were intended to provide actual beer for the living dead.

Everything important in a tomb, from small sculpted servants to the mummy itself, was touched with an adze by a priest in a ritual called "the opening of the mouth". This rite gave magical potency to everything the ka would need in the next life – and its needs included the mummified corpse. The reason for perfectly preserving the corpse was so that its ka could recognise it, and so connect with it to enjoy the food and drink the mummy digested on its behalf.

Spirit and body were mysteriously connected. It's not that Egyptians believed that the mummy could get up and chase people round museums – but they did believe that the dead person's spiritual ka form, which needed the mummy to exist, could leave the tomb and walk around. There are statues of it doing just that.

So what? People believe all kinds of things. But the ancient Egyptians believed in their conquest of death for at least 3,000 years and repeated their spells and rituals over and over again. Their art is incredibly powerful because it is full of the confidence and faith of those rituals. It is truly magical art. Looking at the painted caskets in the mummy store I am moved by the conviction they communicate that death is not the end, but only the beginning of a strange adventure.

The door closes. The eternal night of the tomb returns. The young man's painted face looks calmly into the eyes of his ka.

Ancient Lives: New Discoveries is at the British Museum, London WC1, until 30 November. Tickets: 020-7323 8181.