Cindy Warmbier sent three huge Chinese-style lanterns up into the sky over Cincinnati on December 12 last year. "I love you, Otto," she said as they floated away, imagining that her son, turning 22 that day, might see them from wherever he was being held in North Korea. Then she sang him "Happy Birthday."
If ordinary Americans are alarmed about the current tensions with North Korea, imagine how Fred and Cindy Warmbier feel.
Through two nuclear tests and dozens of missile launches, while Kim Jong Un has been threatening to "ruthlessly ravage" the United States and President Trump has been sending warships to the Korean Peninsula, their son Otto has been detained in North Korea.
"We've not seen or heard from Otto in 16 months," Fred Warmbier said. He and Cindy were speaking over Skype from their home in Wyoming, a Cincinnati suburb. "We don't know if Otto still exists."
When Otto was detained on January 2 last year, US officials advised them to remain silent to avoid antagonising North Korea and prolonging their son's detention, they said.
But they have had enough.
"The era of strategic patience for the Warmbier family is over," said Fred, echoing a line from top members of the Trump administration who have declared an end to the Obama era policy of waiting for the North Korean regime to return to nuclear negotiations.
"With the last administration, Otto seemed to be an unwanted distraction and they urged us to keep quiet," Fred said. "Now the new administration is there, so we've decided to start speaking out."
In recent years, North Korea has periodically detained American citizens, some of them tourists and some of them Korean Americans involved in development work.
Previous detainees have been released after high-profile Americans - including former presidents Bill Clinton and Jimmy Carter - flew to Pyongyang to plead for them, giving the regime a propaganda victory. But North Korea has not even responded to offers to send someone for the current detainees, according to a person involved in the process.
Three Americans are being held in North Korea: former Virginia resident Kim Dong-chul, who was working in a special economic zone in the North; Tony Kim, a professor teaching for a month at a university in Pyongyang who was detained just last weekend; and Otto.
Then a 21-year-old economics major at the University of Virginia, Otto decided to go to North Korea on his way to Hong Kong for a January study-abroad trip last year.
"He was curious about their culture, and he wanted to meet the people of North Korea," Fred said. He had done lots of research and decided on the Young Pioneers travel company because it targeted young, adventurous people like him.
Although North Korea is one of the most isolated countries on the planet, it has been trying to encourage tourism in recent years, and a handful of companies regularly take groups there without incident.
The State Department, however, has steadily ratcheted up its travel warning for North Korea, noting the risk of arbitrary detention. The United States has no diplomatic relations with Pyongyang and is represented there by the Swedish Embassy.
On Otto's final night in Pyongyang, New Year's Eve, he appears to have gone to a staff-only floor of his hotel and attempted to take down a large propaganda sign lauding the regime.
He was charged with "hostile acts against the state" and after an hour-long trial in March, sentenced to 15 years in prison with hard labour. That was the last time Otto was seen in public, and Swedish diplomats have been denied access to him since then.
In the absence of other information about him, some quarters of the Internet have been less than sympathetic to Otto. But he is not some reckless kid who went to North Korea on a lark, his parents say.
"This is somebody who has never been in trouble in his life," Cindy said. Otto was salutatorian at Wyoming High School and a National Merit scholar, captain of the soccer team and homecoming king.
Fred and Cindy were wary about bragging about their son, but they wanted people to know what kind of person he is.
At U-Va., Otto was in a programme for top students. Cindy remembered being struck when they first visited the university by its emphasis on the importance of seeing the world.
Otto spent a summer studying at the London School of Economics and had enough credits to graduate as a sophomore. He had already passed the first level required to become a certified financial analyst and had been offered a job to start after graduation.
"Why would you say no to a kid like this?" Cindy said. Plus, Otto had traveled overseas plenty of times before, including to Europe with his family twice, Israel, Ecuador and Cuba.
Until Otto's arrest, the Warmbiers had been living the archetypal American Dream.
Fred went to work straight after high school, first in real estate. They now run a metal- finishing business whose clients include Whirlpool and General Motors, and Cindy is studying for a master's degree in management. They have a nice house and three children.
But they don't know whether their oldest son is breaking rocks in a labour camp or sitting in some guesthouse in Pyongyang. Either way, Fred said, "there's no way that this crime reaches anywhere near this level of punishment."
The Warmbiers acknowledge the enormity of the tensions between Pyongyang and Washington, but they are clearly frustrated by what they see as the low priority officials have placed on freeing their son.
"We know that the administration has been challenged by bigger issues than Otto, but we don't understand why diplomacy on a different track to get Otto and the other detainees out can't be going on at the same time," Cindy said.
The Warmbiers met this week with Joseph Yun, the State Department's special representative for North Korea policy. A department spokesman said he had nothing to add beyond Yun's private discussions with the family.
But the Warmbiers hope the new administration will put more emphasis on securing their son's release.
"I'm hoping that there will be dialogue, because without dialogue, I don't see how anything will be resolved," Cindy said. "And instead of focusing on the bigger issues, how about focusing on some things where there might be some resolution? Then you have a positive starting point."
In the meantime, the Warmbiers have been trying to get on with their lives and enable their younger children, Austin and Greta, to get on with theirs. "If we are nonfunctioning and depressed, then they've not only imprisoned Otto, they've imprisoned us, too," Cindy said.
Fred has been keeping a family journal and they've been collecting souvenirs - a shirt from a family vacation in Hawaii, a Chicago Cubs jersey after the team won the World Series - so Otto can catch up when he comes back.
"We miss him," said Fred, "and we're going to get him back."