In a corner of the shooting range yesterday afternoon, a chicken-rice eating, laksa-loving Russian is cleaning a Singaporean's rifle with devotion.
He kneels, he swabs the barrel of Jasmine Ser's gun, he jokes: "If you see a guy with grey hair here, he must be a coach."
Kirill Ivanov's hair is silver and on his 54-year-old face are carved the long, slim trenches of time.
He has - in the morning during competition - been studying Ser, who sets an Asian record in the 50m three-positions qualification and then folds with inexperience in the final. I have been studying him.
Ivanov, as we sit together for a while, is a monk of immaculate restraint. If he is not in control, how can he expect his athlete to be?
He draws circles in his notebook, registers every score and fills mental files with every fidget and frown she makes: "I'm looking at her body stability, gun stability, recoil control, emotional control."
Only once, after two 9s, does he emit a gentle "ohhh" and I am drawn to his quiet agony.
"If I don't have emotion, I don't have grey (hair)," he says. He can't shoot for her, yet his heartbeat is vaguely connected to her trigger.
Later, as he cleans the rifle, Ser arrives and sits across him in whispering distance.
She has lost here, yet they are already planning how to win somewhere else. Teacher and pupil start to strip down the final. Muscovite and Singaporean chasing greatness together.
It is an image which inspires for it reflects sports' enduring ability to dissolve borders. In increasingly insular societies, these tiny cross-cultural relationships remind us that knowledge need not be guarded.
In the simple transfer of rifle-holding technique rests a lesson in humility: that we can still learn from each other.
At these Games, Singapore are assisted by coaches from Hungary to Peru and from Thailand to South Africa. There is not a continent we will not investigate for help, yet we have company.
India have found wrestling expertise in a Georgian and befriended a Cuban in boxing. Accents may differ, and culinary preferences collide, but a hunger for a medal is both a glue and a common language.
Gentle ironies are at work. China teach the world sport, yet swimmer Sun Yang was honed in Australia. Even beyond these Games, sport preaches an international understanding.
British runner Mo Farah is trained by American Alberto Salazar while India's cricket team, raised from a pool of a billion experts, are managed by a fellow from Zimbabwe, a nation of 14 million, who prefer football.
If travellers of an older time carried maps, these short-panted coaching wanderers carry laptops with data on biomechanics. They teach us, yet they learn, too.