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.
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.
He looks down, lost in thought.
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:
In the background is a patient he treated the day before.
He is convinced the snipers are playing with their victims:
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.
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.