MOSCOW — For some, a seat in Row 13 might have seemed like a bad omen, but for a flight into the hands of a government you are sure tried to poison you, it's likely such superstitions were the least of Alexei Navalny's concerns.

Five months after he arrived on a plane to Berlin unconscious and fighting for his life after being poisoned with a nerve agent, Russian opposition leader Navalny flew back to his home country in the knowledge that his decision will bring almost certain detention by the regime that is accused of trying to kill him and has repeatedly arrested him.

But as he boarded Flight DP 936 to Moscow on Sunday, Navalny shrugged off the threats to his life and freedom. “Are you not scared, Alexei?” a reporter asked him, as he pushed through a scrum of journalists looking for his seat. “I feel great,” he responded. “In Germany it was also good, but returning home is always better.”

What does he expect in Moscow?

“Wonderful weather,” he joked. “And I expect a warm welcome that I finally returned to my home city.”

Ground staff in Berlin had given instructions to passengers not to film or take pictures on the plane, but their edicts immediately crumbled as boarding began and everyone took selfies with the cabin crew.

As the wheels went up, with press and supporters confined to their seats, the gravity showed on the faces of Navalny and his wife, Yulia, who were accompanied by a lawyer and a spokeswoman. Navalny looked out of the window, pressing his fingers to his forehead, while she raised her eyes to the ceiling, the stress clear.

As soon as the seat belt sign went off, the reporters descended again. “Mr. Navalny, can you just say a word for Israeli TV,” shouted one, as Navalny responded to English questions in Russian.

The couple tried to watch an episode of the animated series “Rick and Morty,” but there was little space for diversion.

Some of the plane’s regular passengers were bemused. A 51-year-old German national named Frank was flying to Moscow to visit his wife. “It’s crazy, simple as that,” he said, nodding toward Navalny in the row in front.

He asked that his full name not be published as he flew into Russia with the country’s leading opposition voice. He’d booked his flight weeks ago and said that he hadn’t felt the need to change it. “The second time, they will try another way,” he joked, referring to the fact that Navalny had fallen sick with a nerve agent in the Novichok family on the last flight he boarded.

Outside, the frosted fields of Germany gave way to snowy white expanses. In quiet moments Navalny and his wife shared a kiss through their surgical masks, and he draped an arm around her shoulder. His lawyer, Olga Mikhailova, explained the nuances of Navalny’s case to reporters, describing him as her most complicated client.

The captain occasionally broke in with updates on the location, Minsk to the left, and then Moscow. The cabin crew requested a group photo and the plane began its descent. But it didn’t last long.

There’s a “technical” problem with landing at Moscow Vnukovo, the captain explained. A murmur of laughter went up among the passengers. “There’s the technical problem,” said Frank, motioning toward Navalny.

The captain said the conditions were not appropriate for landing at the airport where crowds of Navalny’s supporters had gathered to welcome him home. The flight might be diverted to Moscow’s Sheremetyevo airport, less than 30 miles away. “The weather is fantastic there,” he added.

Navalny beckoned to the reporters. Russian authorities are keeping planes in the air because they are afraid, he said.

The plane finally touched down in Sheremetyevo. Is he afraid? A reporter asks. “No,” he responded. He apologized to other passengers for the diversion, before making his way to the immigration counter, where several uniformed security officers arrived and asked for his passport. Authorities said he had violated the terms of a six-year-old suspended sentence by going to Germany.

“Sure, let’s go,” he eventually relented. “But I want my lawyer to come.”

Mikhailova interjected: “You are detaining him, but all of the relevant documents are with me.”

But they denied his request for a lawyer. He shared a final embrace with his wife and was led away to a side room alone, the door closed firmly behind him.

Isabelle Khurshudyan in Moscow contributed to this report.