Pobeda flight DP936 was a few minutes into its descent towards Moscow's Vnukovo airport, where thousands of supporters of poisoned Kremlin critic Alexei Navalny were waiting to meet him on his return to Russia, when the flight captain said he could not land as planned.
There were "technical difficulties", he said, before adding, audibly amused: "Instead we will calmly make our way to Sheremetyevo airport ... where the weather is great!"
It was the first sign to those on board that Navalny's return from Berlin, where he had been treated since August after being attacked in Russia with the military-grade nerve agent Novichok, was not going smoothly.
After landing, he sat in the plane, looking out of the window onto a dark, snow-covered runaway and a handful of airport workers in fluorescent vests, holding his wife Yulia's hand in silence.
His lawyer, also on board, had said she did not know whether the Kremlin's most vocal and effective critic would be arrested.
The 44-year-old is accused of flouting the terms of a suspended sentence for embezzlement in a case that he says was trumped up but could see him jailed for 3-1/2 years.
He entered Terminal D with an energetic step. Stopping in front of a glowing, wall-sized panel showing the Kremlin and the Russian flag, he said he had never considered not returning.
Speaking to reporters, he thanked the nurses and doctors in Germany who had treated him for the effects of the toxin, from a family originally developed by the Soviet military.
But he said that this was, nevertheless, his best day of the past five months.
"This is my home," he said. "I'm not afraid."
'You're Detaining Me'
Then, at border control, things took a turn for the worse.
Standing in the narrow corridor of the glass-panelled passport control booth, Navalny was approached by an official who asked him to step away to "clarify the circumstances" of his entry.
His wife and lawyer stood right by, but were already separated from him by the metal passport control gate. His lawyer asked on what grounds he was being prevented from entering, but did not receive a clear response.
Four police officers in black face masks came up to the booth and also demanded Navalny come with them.
"Are you detaining me?" Navalny asked. "You're detaining me," he said, repeatedly. In that case, he said, he would like his lawyer to join him.
The back-and-forth continued for around three minutes, until Navalny turned back to his wife.
Standing either side of the passport gate, the couple embraced, before Navalny turned around to head away with the police.
His wife, his lawyer and his press secretary headed towards baggage reclaim and sat down, Yulia looking calm. She asked the journalists present to give her time to gather her thoughts.
Then she walked out into the arrivals hall to be met by a rush of supporters who applauded and chanted: "Yulia! Yulia!" and "Russia will be free!". Some stood on the balconies above. One gave her a bouquet.
She was then met by Navalny's brother, Oleg, who spent three-and-a-half years in jail for the same crime that Alexei was convicted of.
Standing outside in the icy evening air, Yulia Navalnaya addressed the crowd: "Alexei said today that he is not afraid. I am not afraid either. And I call upon you all not to be afraid."
Then she left, and the crowd gradually dispersed.
Navalny himself, as far as anyone knew, remained in the airport's transit zone.