'We clean anything’ – that’s what our advert said. I sent it to undertakers, police and housing associations... and two days later, we got a call-out to our first corpse.

A local solicitor rang to say a man’s body had been found at a property and had probably been lying there for six weeks. ‘Uh-huh,’ I said, trying to sound as if this was the sort of thing we dealt with all the time. There was a pause. ‘There’s one more thing you should know.’

I heard the sound of someone trying to work out how to best phrase something, then just giving up. ‘His dog has been in there with him and has eaten his face and most of one of his legs.’

‘I see,’ I said. I named a price, and the lawyer didn’t flinch. Biohazard clean-up, I was starting to discover, was very different to other kinds of cleaning jobs. People don’t haggle about the cost. They’re paying precisely so they don’t have to think about what the job entails.

That’s what first drew me to this line of work: the money. After starting as a window cleaner in West Wales, I had been working round the clock at every job I could get.

One short-notice job, cleaning the Great Glasshouse at the National Botanic Garden Wales, was so all-consuming that I was leaving the house every morning at 5am and getting home at 10pm – with my young wife looking after two toddlers on her own.

One night they weren’t there, and I found a note on the kitchen table: ‘If this is what life is going to be like, I’ll be at my parents’.’

Clearly, this couldn’t carry on. But I couldn’t see a way out, until the day a woman in Aberystwyth asked me to clean her bath. ‘It’s a bit of a state, I’m afraid,’ she said. ‘The tenant wasn’t the tidiest.’

She wasn’t kidding. As soon as I reached the top of the stairs, the smell hit me. The bathroom was carpeted in about two feet of filthy toilet paper, and the bath was full to the brim with urine and faeces. In the other corner was an overflowing toilet.

‘How much do you charge?’ she asked. My head reeling, I picked the biggest number that seemed plausible for a day’s work: £2,000. ‘Done!’ she said, and I realised as she shook my hand that she was filled with complete gratitude.

In the pub that weekend, I was regaling a couple of mates with the gruesome story of how we cleared up that bathroom. ‘You could not pay me any amount of money to do that,’ one said, and it was like a light bulb going on. ‘Any amount of money’ was waiting for the window cleaner who was ready to do the jobs that made other people weak at the knees.

I renamed my company Ultima, because ultimately there was nothing we wouldn’t clean.

Still, after signing up for a short course that made me a fully qualified biohazard cleaner, I couldn’t have imagined the sight that greeted me on that first job, at a dilapidated farmhouse at the end of a rural track.

As I opened the door, a swarm of bluebottles flew at me. A decomposing body is a mass of pathogens and infectious germs. But bluebottles aren’t great hosts for viruses. This is because any liquids dry out quickly as they fly. They are often moving through sunlight, which kills viruses, and they are constantly cleaning themselves.

After the flies came the smell – part rotting meat, part rotten eggs and part sewer, with a rich, sulphurous tang like garlic. It was a thick, wet smell that pushed its fingers down the back of your throat. Even through my mask, it was close to overwhelming. Never have I been more grateful for my double-layered, full body suit made from plastic polymer, and double-thick gloves, shatterproof goggles and heavy-duty boots.

In the centre of the room was a dark stain. A human body is between 60 and 70 per cent water. About four minutes after your heart stops, the process of autolysis, or ‘self-digestion’, begins.

Quite quickly, everything starts to leak out of you. At the same time the flies go to work, laying eggs that will hatch as maggots. Blowflies, like bluebottles and greenbottles, can smell decaying matter from as far as a mile away.

There can be tens of thousands of flies on one corpse. In fact, forensic scientists use the life cycle of flies to broadly estimate a time of death.

As it decomposes, a human body produces up to 500 chemical compounds and around 15 gallons of liquid, which soaks into whatever the body is resting upon. The average office water-cooler holds five gallons, so imagine three of those dumped onto the floor.

The initial purge fluid – made up of water, fat and other cellular material, which is forced out of the body by internal gases – is red.

But, pretty quickly, because of the iron-rich haemoglobin in it, it turns dark brown, almost black. It’s the same chemical reaction that occurs when metal rusts.

Then there’s the fat, like a thick layer of dark sludge. The average body contains enough to fill about four two-litre drinks bottles... and it has to go somewhere.

We tackled that room inch by inch, foot by foot – everything in front of us dirty, everything behind us clean. With hindsight, I realise we were lucky not to become ill. Because we were in a rural environment, there were rodent droppings, which leave behind pathogens that can survive for days. Some of them can be transmitted when the liquid is dried. Rat and mouse droppings can also contain salmonella and leptospirosis, which can lead to kidney and liver failure and meningitis.

There is also a nasty lung condition resulting from hantavirus – the same pathogen that has caused the death of three passengers aboard the MV Hondius cruise ship in the past month. Left untreated, hantavirus pulmonary syndrome has a mortality rate of almost 40 per cent.

But once the job was done, my team and I had earned comfortably more than the average monthly wage for one night’s work. I wasn’t going back to cleaning windows.

At another farmhouse in rural Wales, we found a dark stain by the side of the bed. The former occupant had died of natural causes and lain there for between six to eight weeks before a neighbour alerted the authorities.

The carpet made an odd squishing noise when we walked on it. We started cutting it up and bagging it, and discovered the chipboard floor beneath it was soaked.

When we lifted it, that’s when we found the maggots – a slick, white mass, the colour of single cream, roiling like fish after bait.

Six to eight weeks might sound a long time for a body to lie undiscovered. But we once sent a team to a job along with an undertaker and they walked into the lounge to find a skeleton sat in the armchair wearing an intact leather belt and leather shoes on its skeleton feet.

It turned out the body had been there for 15 years before it was discovered. It might seem remarkable, but sometimes families move away, or there’s a falling out. Neighbours aren’t close. Bills are paid automatically so no alarm is raised. It can happen.

Another time, I was asked to attend a property by a very irate lettings agent who told me the tenant had let the place go to ruin. The neighbours had been complaining about the state of it and now he’d run off back home overseas, leaving a trail of unpaid bills.

Finally, after a year of legal process, the homeowner had regained possession and wanted it cleaning. I collected the keys and went into the flat. I could smell something decomposing and prepared myself to find a dog or cat somewhere. In the kitchen was an open door with a flight of stairs leading down to what was presumably a basement.

The electricity had been switched off, so I retrieved my torch and started to head down the stairs. The smell got stronger. There, at the bottom, I could see the shape of the former tenant.

I went and called the estate agent and explained he hadn’t done a runner but was in fact lying at the bottom of the basement steps. I hoped he had died quickly.

My childhood was a happy one, but it was also good preparation for this work. I grew up on a farm, and death was a natural part of existence. Chickens and rabbits had to be killed for the pot. Cows gave birth but also went to the slaughterhouse. I helped with the lambing, and sometimes that meant dealing with carcasses.

But nothing could have prepared me for some of the jobs I’ve done.

I have cleaned a house where one person bleeding out had covered pretty much the entire ground floor with bloodstains, as they’d dragged themselves along before collapsing in their hallway.

Everything we clean up tells some sort of story, often of the last moments of a life. The most poignant can be the result of suicide, as a record of the frantic moment when the person realised what they had done, but too late. The panic, the urgency, the desperation is there for you to see.

We have often been called to clean rented cars that have been involved in crime – frequently violent. We’ve cleaned cars that have been the scene of fatal stabbings and shootings, where blood has pooled everywhere. Bloodstains will be visible where the victim’s hands have scrabbled around or tried to stop the blood flow.

Often there are items of clothing left in there, along with personal belongings. Or there might be something that brings it home that they were going about their day – perhaps a half-drunk carton of drink, or a lipstick in the door well. Or there might be a kid’s car seat in the back – that always gets me.

We attend the aftermath of traffic accidents, when every minute counts if police are to reopen the road quickly. Some situations have been more taxing than others – for instance, on a freezing cold night, I was confronted by oil and body fluid where a human body had hit the ground: the car had gone over it and taken the oil sump off.

Having to clean this up at 2am when the temperature was minus 1C was incredibly difficult. Cleaning fluids froze on the surfaces.

There was one case, a couple of years back, that really got to me. We were called to clean the aftermath of a violent death. It was a normal suburban house. Neat and tidy. Coats on hooks. Keys in a bowl by the door.

But the kitchen was carnage. There was just so much blood. It was everywhere: along the top of the Venetian blinds, pooled in cutlery drawers, on the cupboards, on the floor, on the walls, on the worktops, on the door handles and even inside the washing machine.

There were handprints, fingerprints, fine droplets from the violent swinging of an object covered in blood. We were there for hours, working our way slowly through the room, when a police officer came in. We looked at her.

‘We got him. The bloke who did this.’ She gestured at the kitchen.

‘It was the husband. He was sitting around the corner in the pub. Having a pint.’

That night, I was filling the dishwasher when I saw the exact same sort of seal that only a few hours before I had been cleaning the blood from and it hit me. How does that happen? How does someone do that? To someone they love – or once loved? To anyone?

I suddenly felt like my chest was tight. My wife Linz came and asked me what the matter was, but I just shook my head. It took me days to be able to talk about it with anyone. I couldn’t work out why this room affected me so much when I’d stood in so many horrific scenes. Why would this one be the one that got me?

I reckon it must be like filling a bucket. There’s always a final drop before it starts to overflow.

A death, any death, is certain to change the universe of at least one person – and often many more. But, like the ripples of a stone thrown into a pond, as it moves outwards, the force becomes smaller.

A tragedy becomes an incident, becomes a shame, then an inconvenient logistical issue that needs solving. The world has to keep turning. Anyone who has ever experienced grief knows that odd feeling when you realise that your world has changed for ever... but for other people, it is exactly the same as it was yesterday.

Someone has to get things back to normal. And that’s my job.

© Ben Giles 2026

Adapted from The Specialist by Ben Giles, to be published by HarperNorth on May 21, priced £18.99. To order a copy for £17.09 (offer valid to May 23; UK p&p free on orders over £25) go to www.mailshop.co.uk/books or call 020 3176 2937.

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