We cross in silence through an extensive pine forest. We walk over the tracks that the cars have made on the light, damp, unpaved ground. A few minutes later, a disconcerting sight appears: dozens of men and women in blue coats, masks, helmets and bulletproof vests. They are standing among the trees. They are holding shovels in their hands and their eyes cast a shadow that presages the worst.
We continue walking and it turns into a real horror film. On the right side of the road, there are huge ditches dug through the pine trees; on the left side, hundreds of individual graves stretch as far as the eye can see.
Some of them have just been opened, and technicians from the Kharkiv Crime Laboratory are removing bodies in an advanced state of decomposition. Most of the corpses are buried without a coffin, wrapped in a blanket or inside a plastic bag. An indescribable smell pervades everything.
This is a new mass grave found in a Ukrainian town after the Russian occupation. This time it was in Izyum, the most important town in the south of Kharkiv. Today is only the first day of work.
The authorities claim that there are at least 445 bodies here - maybe more - and among the first corpses they have pulled out of the ground they have already found signs of torture. Some are handcuffed, others show signs of violent deaths from gunshots and artillery fire.
On the right-hand side of the road, three technicians are working on a mass grave. Their faces are discomposed. They pull the plastic bags they are digging up out of the earth, open them and check their contents. Then they pick up the bundle, each one from a corner, and place it in an ever-lengthening line where forensic doctors work.
As they return to the grave to look for the next body, one of them stops for a moment and lights a cigarette. His trembling hands say it all. I think to myself, "I hope the tobacco smoke will mask a little of the smell in the air, condensed by the humidity of a rainy day", but I don't think that cigarette will do him much good.
When the coroner opens the bag containing the last body to be exhumed, there are murmurs among the policemen who are taking notes of the process. The body is handcuffed. The evidence of torture and war crimes is unquestionable.
Despite the shock of seeing it live, it comes as no surprise to them. When the Ukrainian army recaptured Izyum on 11 September, they found ten torture centres scattered around the city. So it is to be expected that there will be many more victims with signs of martyrdom buried here.
Documenting each of these cases is crucial if an international war crimes investigation is to be opened, although the question remains as to who will pay for them. Today it is hard to imagine Putin sitting before the Hague Tribunal, answering for this and other atrocities, such as the systematic bombing of civilians. But investigations must be conducted nonetheless.
The wooded area where the graves were found is very close to the city cemetery, but the burials have nothing to do with those in the necropolis. Alongside the huge mass graves, on this side of the wall there are hundreds of unmarked graves, crowned by a modest wooden cross with a number. 336, 337, 338...
It is distressing to see how far the numbering goes, not knowing whether under each cross lies a child or an old man, a fighter or a doctor, a Ukrainian or a Russian. The bodies that have already been exhumed are placed next to the crosses, waiting for one of the forensic doctors to pass by for a preliminary analysis.
One of the blue-robed technicians rushes out of one of these graves, where he was digging, and his colleagues help him pour water into his eyes. It seems that with the last shovelful of earth he has uncovered a new corpse. After a minute, he goes back into the hole, along with another companion, and pulls out the body.
The coroner takes his time with each body. He observes them slowly, then dictates some notes to his assistants. Then he opens the clothes - totally rotten in most cases - and looks for clues as to the cause of death. The process takes a while.
When they are finished, the corpses are placed in plastic bags and labelled with the data that has been collected. There are more than 200 technicians, forensic experts and police from the Kharkiv Investigative Unit working at the same time. They plan to exhume about 20 bodies per day, so the work will take several weeks.
Mixed in these graves are those who have died of natural causes during the six months of Russian occupation, along with those who have perished under bombs and those who have been tortured and killed by the Kremlin's army. The investigations will take months - perhaps years - to resolve each case.