At just after 1am on the morning of October 23 last year, Maurice Robinson, a lorry driver from Craigavon, Co Armagh, got a Snapchat message from his boss. The message read: "Give them some air but don't let them out". Robinson replied with a thumbs up emoji.
He had just picked up a refrigerated lorry container from the Port of Purfleet in Essex and pulled into Eastern Avenue not far from the port.
CCTV recorded the moment he got out of the cab and walked around to the back of the lorry.
When he opened the door a billow of vapour escaped, a cloud of hopes and dreams evaporated. There were 39 bodies inside.
A police forensic drawing recorded the positions of the bodies inside the lorry. Sixteen of the corpses are positioned at the back of the container, by the doors. Some of the figures are lying on top of each other, others are in pairs lying side by side, a couple appear to be embracing.
The computer aided design of the drawing means that the figures are geometric. This is the architecture of nightmares.
The drawing doesn't show the metal pole inside which was used to try to pry open the doors or the bloodied marks where people tried to claw their way out. The drawing doesn't tell you who these people are, among them: a married couple, a 15-year-old boy, twins.
In all, 39 Vietnamese people between the ages of 15 and 44 who had paid smugglers to get them to Britain died inside the container.
The lorry's refrigeration unit was not turned on and temperatures reached 38 degrees, the occupants overheated and ran out of oxygen.
By the time Maurice Robinson opened the back of the lorry the 39 people had been dead for hours. He called his boss Ronan Hughes, a haulier from Tyholland, Co Monaghan. Thirty minutes after opening the doors he calls 999.
"There's loads of them. There's immigrants in the back. They're all lying on the ground."
The operator asks whether they are breathing or not. He replies: "I don't think so, no."
It's difficult to imagine what it was like for the police officers who first arrived on the scene that morning and had to enter the lorry to assess what had happened.
One of the officers was a recent recruit and was given counselling for months afterwards.
Scores of mobile phones were found in the lorry belonging to the people who died.
They had used their phones to see in the darkness and to try to message loved ones, in vain, as they slipped away. One of the phones belonged to 26 year old Pham Thi Tra My.
It is over a year since her parents found out about their daughter's death. On the living room wall of their house, in the Can Loc District of Vietnam's central Ha Tinh Province, there is a shrine to Tra My. The flowers on the shelf around her photograph are freshly cut.
"From the time she was born, she was very gentle and beautiful. She thought about the family all the time," says her father.
On her Facebook page there is a video of her on a visit to the Bana Hills Golden Bridge in Central Vietnam. She is videoing herself. The wind is blowing her hair into her face. She swings the camera phone around, over her shoulder you can see a newly married couple having wedding photos taken. Tra My smiles.
According to her father everything about his daughter was completely authentic but like many millennials there was a disconnect between the life she projected online and the one she actually lived.
The family is not particularly poor by the standards of their home town but a couple of years ago they ended up in serious debt. Tra My's brother had got a loan to buy a taxi which he was using to earn money for the family. He had been involved in a serious accident though and the car had been written off. The family were in dire straits.
The expectation was that every family member contributes to the family's collective wealth so Tra My volunteered to go work in the UK in a nail bar.
In order to get to the warren of alleyways where the family live you drive passed large houses built by remittances from people living in the UK.
The World Bank estimates that $17bn was sent home by Vietnamese workers living abroad last year - that is the equivalent to 6.5% of Vietnam's GDP.
Although pre-Covid, Vietnam's economy was performing well, the wealth is concentrated in the cities. Thousands of young people from places like Ha Tinh opt to leave for the UK to work in restaurants and nail bars. Tra My had told her father that she expected to earn £1,600 a month working in a nail bar in the UK. The average monthly salary in Ha Tinh province is the equivalent to £100.
The smuggling package the family opted for would cost £30,000. Even with that exorbitant initial outlay, Tra My's family decided it was worth it. If their daughter managed to send back £1,000 a month, after five years the family would have paid back the smuggling fee and still have thousands in the bank. In other words, the maths added up.
So they turned to a group of Vietnamese people smugglers in their neighbourhood. A few months ago three men and a woman were sentenced for brokering the smuggling package that Tra My's family paid for.
One of the men was even related by marriage to them. The family mortgaged land and opted for the most expensive smuggling package for their daughter, the most direct route.
In October last year Tra My travelled by car and bus to China. The Vietnamese network organised a fake Chinese passport and tourist visa. She told her family she had spent 10 days in China then flew directly to Paris. Usually though smuggling routes go through Russia or Turkey then overland to France and Belgium.
The family told us they had paid the equivalent of £16,000 for this leg alone. On October 16 Tra My arrived in Paris. She was brought to a Vietnamese run 'safe house' in Creteil, on the outskirts of the city. Up until this point Tra My was being 'looked after' by Vietnamese smuggling networks. That was about to change though.
The final fatal leg of Tra My's journey would cost an extra £14,000: Paris to London.
On October 22 last year Tra My and the others were picked up near the safe house in Paris by a fleet of taxis. They were driven north to the village of Bierne, near the French border with Belgium. Others travelled from Brussels and Dunkirk.
The rendezvous point was a farm outside the village. The Paris to London leg was the riskiest part of the journey as far as the criminals were concerned. The £14,000 would be paid on arrival via the Vietnamese network to two other criminal gangs working together - the East Europeans and the Irish.
Which brings us to Tyholland, Co Monaghan. It is where Ronan Hughes lived - a world away from Ha Tinh Province, Vietnam.
He ran a haulage company and employed several lorry drivers on a freelance basis. His house is up a bothareen, a stone's throw from the border. His fleet of lorries were spread out across different yards both sides of the border.
As well as the legitimate side of the business, Hughes was a logistics man for a host of crime groups. Retired Garda Superintendent Fergus Trayner grew up in these parts and knows the Hughes operation well.
According to him, Ronan Hughes provided 'wheels for hire' for whoever would pay.
"Basically it's just about the product and the movement of that product. I wouldn't say that Ronan Hughes has any particular allegiance to any particular gang. It's just about product."
Fergus Trayner tells us that Hughes cut his teeth smuggling cigarettes and alcohol and then graduated up to the most lucrative consignments of all: people. In August this year he pleaded guilty to 39 counts of manslaughter and also to conspiracy to assist unlawful immigration. In other words, his career ended transporting bodies, including that of Tra My's. On the morning of October 22 last year she was hiding inside a barn on a farm in the village of Bierne having being dropped there by a taxi.
An eyewitness, told us that she saw a refrigerated lorry pull up that morning and nine Vietnamese people ran out of the barn and got in the back of the lorry.
This was a well oiled machine. The gang had successfully smuggled people into the UK many times before. Christopher Kennedy, for example, another one of Hughes's lorry drivers, from Armagh, was convicted on Monday yesterday for previous successful attempts at smuggling lorry loads of people into Britain.
So, how often were the network doing this? Xavier Delrieu is the boss at Ocriest, a special unit of French police investigating illegal immigration.
"What we can say about this network is that it had been active for many years. Based on our surveillance there was at least one crossing or attempted crossing per week. That's, at a minimum, 50 a year. And that's just this network, we know that there are others."
On other occasions the gang transported 20 people per lorry. This time was different. A previous attempt had not gone to plan so the smugglers decided to double up the numbers inside the container this time. The sky over that farm in Bierne was probably the last natural light that Tra My and the others ever saw. The lorry's refrigeration unit was off and there were too many people inside so the oxygen started running out and the temperature started to rise the moment the doors closed.
It was also revealed in court that at least one person showed up late to the Bierne rendezvous point and missed the lorry that was to become an articulated coffin.
At around 10.40am Harrison's truck left Bierne for Belgium. A few hours later he arrived in the Port of Zeebrugge. He dropped the trailer off ready to be loaded onto the Cargo ship, the Clementine.
If the people inside had made it alive to Britain, they would have been first brought to a farm in Kent where they would have been collected off the lorry and brought by car to a series of 'safe houses' in London.
This brings us to the other criminal gang, the Eastern European middlemen. They were a group of Romanian and Albanian criminals who were connecting the people being smuggled by the Vietnamese network to the Irish logistics arm of the operation and then transporting them to London.
Gheorghe Nica, a Romanian living in Basildon, Essex, was a key player. On previous runs he had organised drivers to pick up the Vietnamese once in Britain.
The East Europeans appeared to be acting as the go-betweens both in France and the UK, making sure that all involved knew where the rendezvous points were.
They also paid Ronan Hughes and his men their cut of the smuggling fee paid by Vietnamese families.
Back at the Port in Zeebrugge the container was loaded onto the cargo ship, the Clementine, at 3pm on October 22.
Inside the container, in the dark, 39 people whose fate is now all but sealed. About half an hour later the ship set sail on its eight hour crossing and the claustrophobic nightmare continues in earnest - there are eight hours to go and the temperature inside is 28C. By the time the container is half way across the North Sea, the temperature is approaching 38C. The people are panicking. Tra My tries to call her family six times but there's no connection and she can't get through.
She is not alone. Nguyen Dinh Luong, who is 20, tries to send a video message to his family.
"I have to go now. I'm sorry. It's all my fault"
Nguyen Tho Tuan (25) tries to message his wife and children: "I can't take care of you, I'm sorry"
After failing to get through on the phone, Tra My tries to send her mother one last message. It doesn't immediately send because of poor reception but when Tra My's phone connects to a British network the message does send. By this point, though, Tra My has died.
The message read: "My path to abroad doesn't succeed. Mum, I love you so much. I'm dying bcoz I can't breath ... I am sorry Mum."
Paraic O'Brien is a reporter for Channel 4 News
A family handout photo issued by Essex Police of (left to right top row) Dinh Dinh Binh, Nguyen Minh Quang, Nguyen Huy Phong, Le Van Ha, Nguyen Van Hiep, Bui Phan Thang, Nguyen Van Hung, Nguyen Huy Hung, Nguyen Tien Dung, Pham Thi Tra My, (left to right second row) Tran Khanh Tho, Nguyen Van Nhan, Vo Ngoc Nam, Vo Van Linh, Nguyen Ba Vu Hung, Vo Nhan Du, Tran Hai Loc, Tran Manh Hung, Nguyen Thi Van, Bui Thi Nhung, (third row left to right) Hoang Van Tiep, Tran Thi Ngoc, Phan Thi Thanh,Tran Thi Tho, Duong Minh Tuan, Pham Thi Ngoc Oanh, Tran Thi Mai Nhung, Le Trong Thanh, Nguyen Ngoc Ha, Hoang Van Hoi, (bottom row left to right) Tran Ngoc Hieu, Cao Tien Dung, Dinh Dinh Thai Quyen, Dang Huu Tuyen, Nguyen Dinh Luong , Cao Huy Thanh, Nguyen Trong Thai, Nguyen Tho Tuan and Nguyen Dinh Tu, the 39 Vietnamese migrants.