He calls it 'the Sniper's Game'. Some game.
One day children are murdered, the next day it's pregnant women. Unexplained clusters of casualties, different from one day to the next.
David Nott has no other way of explaining many of the injuries he treated during his long, dark days operating in a hospital at the heart of Syria's conflict.
If it's true, it's a heartless, filthy game being played in the middle of a hopeless war.
Hopeless because it's deadlocked; the 'game' is what deadlock looks like.
It begins, typically, in the early morning. Dr Nott and his fellow surgeons have begun another eighteen hour day, treating the gunshot and blast victims of Syria's civil war. He begins to notice a pattern.
One day we'd have pregnant women being brought in with gunshot wounds to the uterus. Not just one or two, but seven or eight, which meant to me they (the snipers) must be targeting pregnant women.
And the following day, we would get people coming in with chest wounds to the right side of the chest.
The next day it would be the left side and no other injuries. Then it would be groin wounds; everybody would come in with a groin wound.
So it seemed to me that there was a death game going on with the snipers
I have seen them myself in the last month; bored gunmen, peering through cracks in the breezeblock walls of their sniper's nest, locked in a conflict neither side seems capable of winning, shooting anything that moves.
In one area at least, where they can spot dozens of civilians to shoot, it seems they have decided to compete with one another in a cruel contest.
The vast majority of the injured and the dead are civilians, nine out of ten, says the soft spoken surgeon who spends most of his year in three of London's top hospitals
The most vulnerable are also victims of Syria's savage game. Children, dozens of them every week, arrive at the overworked hospital in odd clusters.
One day there might be very few, the next, a dozen or more. "A lot of the children were shot in the neck or upper body", says Mr. Nott. And more quickly than adults, they can die in front of the surgeon's eyes, in spite of his best efforts.
They maintain their blood pressure and pulse and then suddenly these drop and they die in front of your eyes.
They bleed to death very quickly. It is a truly shocking thing to deal with.
He looks down, lost in thought.
It's very painful. But if you start to think you can't do your job. If you had a death on the (operating) table, you knew that within half an hour you'd have another patient to deal with.
We filmed David Nott during his most recent five week stint, during which he worked eighteen hour days, most days. One day, his face smeared with blood after an operation, he says:
I've been operating here today under intense difficulty. We've had five gunshot wound patients in the last six to eight hours...we're expecting more and we've just heard there was an airstrike not far away - it's full on.
In the background is a patient he treated the day before.
He's a civilian who was just walking down the street when he was shot, one of the multitude of patients that were shot yesterday. I think we had eight or nine sniper attacks.
Most of the victims are woman and children. I've seen very few fighters since I've been here.
It's pitiful because we receive cases of pregnant ladies who are shot in the uturus and removing dead babies from the uturus is a very unpleasant experience.
He is convinced the snipers are playing with their victims:
There are gunshot wounds to the groin, chest and abdomen but very few wounds to the head, so it means sometimes the snipers are out there to wound and hurt people rather than to kill them outright.
But Syria's death toll of 100,000 and rising tells another story.
Later in the day we see him outside, having a break.
Suddenly he winces, a loud explosion nearby. It begins again. More dead and injured. More victims of the cruel game.
David Nott has worked as an emergency surgeon in war zones for the last twenty years. Normally to be found at Chelsea and Westminster, the Royal Marsden and St. Marys' hospitals, he gives up at least a month of his time every year, risking his life, to help the most vulnerable.
His work has taken him to Bosnia, Sudan, Chad and the Democratic Republic of Congo where he performed a life-saving arm amputation on a boy by taking instructions via text from a colleague in London.
His work in Syria carries appalling risks. Hospitals and medical workers are regularly targeted.
Killing a doctor, according to the grim logic of Syria's war, is better than killing one hundred fighters. A colleague who trained under Dr. Nott was killed in May.
Isa Rahman, A 26-year-old doctor who worked at London's Royal Free Hospital, died when his makeshift clinic in Idlib province was shelled by the Syrian army.
It's extremely dangerous. The snipers are often out there to wound, but we havevery few surgeons. We're short of everything; anaesthetic equipment, painrelieving drugs, medications. Most of the anaesthetics are given by volunteerswho are not trained. They're sometimes shopkeepers.
There is a shortage of everything, except casualties. They are short of supplies, but not courage.
And it takes extraordinary courage to work in the middle of Syria's "Sniper's Game".
David Nott was supported in his work by Syria Relief, a UK-based charity established to send and coordinate a number of charitable activities that are taking place in the UK providing help and support to Syrian families and individuals in need.