After Crimeans voted to leave Ukraine and join Russia, a man in a black raincoat turned up at the gate of the Belbek Air Base to demand that Ukrainian forces holed up inside surrender to Russia.
The Ukrainian commander of the base came out wearing his cap decorated with gold wings, and refused.
The Russian visitor persisted: "From yesterday, you are located on the territory of a foreign state. So I'm giving you your chance to keep your honour as an officer."
"As an officer with honour, I tell you I will stay," retorted Air Force Colonel Yuliy Mamchur.
That act of defiance against the overwhelming force of Russian troops that had put Belbek under siege created a new Ukrainian national hero.
Today, Mamchur is hailed as an officer who stood up to the Russian juggernaut, remained true to his oath as a soldier and held out with his beleaguered unit in Crimea for as long as he could.
After Mamchur refused to cave in, Russian forces overran Belbek with irresistible force and numbers.
Mamchur stood calmly with his men. He led them in singing the Ukrainian national anthem, which begins with the lyrics "Ukraine's glory and freedom are not yet dead".
Russian forces then arrested Mamchur and took him away for questioning.
He withstood five days of sustained intimidation and pressure to defect from his captors, and he was released on Wednesday after that pressure proved futile.
"They tried to get me to renounce my military oath to Ukraine and switch to the Russian army," Mamchur said in a televised interview shortly after his release. "Then they applied psychological pressure, they didn't let me sleep, banging with their rifle butts on the door."
Mamchur is now heading to a hero's welcome in the capital, Kiev.
His saga of resistance began in early March when troops under orders from Moscow swarmed into Crimea. Ukraine's inexperienced government dithered over a response, but Mamchur stuck to his ground whenever the Russians came calling to tell him to leave.
"If there is an order, I will leave. If there is no order, I will stay," he told the man in the raincoat who demanded last week that Belbek stand down.
Displaying a sense of cool under pressure as the inevitable storming of his base neared, Mamchur oversaw an impromptu wedding between two lieutenants - medic Galina Volosyanchik and communications officer Ivan Benera.