It's an hour before the big test starts and the skies above Seoul have gone silent. The government grounds aircraft or re-routes flights to keep students from getting distracted during the biggest test of their lives. It's a college entrance exam known as Suneung, and all South Korean high school seniors take it on the same day each year.
The Suneung is a standardized test much like the American SAT, only the five part, multiple choice exam takes nearly eight hours to complete. And the importance that Korean society places on it makes it far more intense.
On the streets Thursday morning, you could hear more sirens than usual, because anyone running late to the competitive exam can call for a free police escort, to rush them straight to the test site.
The students are greeted at test centers by cheering squads of underclassmen, who carry signs and bang on pots and pans, to support the students when they arrive.
"I came here [at] 5:30am," said cheer squad leader Chansoo Park. He's junior class president at Ichon High School. "There's a lot of students so we have to take a good spot."
Everyone in Korea plays a role in supporting the 600,000 students taking the Suneung. The stock market opened an hour late. So did most businesses. Parents filled up local churches and temples to pray.
"There is this sense that, 'Oh, you're going to fail at life unless you do well in this exam,'" said Daniel Tudor, a former Economist correspondent in South Korea and author of Korea: The Impossible Country.
"To live in modern South Korea is to live with constant pressure. The Suneung exam, it's an emblem," he says.
Students sitting down to the Suneung know it.
"I think I've been preparing since elementary school," says senior Im Hayoon. "I studied about 10 hours every day."
That's typical, says Tudor.
"Korea is very hierarchical, so if you're seen as someone who's not succeeded, you're really made to feel second class," he says.
Success is defined narrowly. Get a high score on the Suneung to get into a high-ranked school. Go to a good school to get hired at a South Korean chaebol — the term for a mighty mega-conglomerate, like Samsung. They power the Korean economy.
"Any market that's worth having is really sewn up by chaebol already. So your best hope would be just to join a chaebol," Tudor says. "You know, if Mark Zuckerberg were Korean, there's absolutely no way he'd be doing what he's doing now. He'd probably be working for Samsung and hating it."
Policy makers are trying to relieve the pressure by encouraging entrepreneurship so students can imagine more creative paths. But all the hulabaloo around the test only seems to add to the exam's intensity.
The message the cheering squads give to their fellow students?
"Relax and get good grades so they will not take the test again next year," Chansoo Park says.
Korean students can retake the test if they don't like their results. But since the Suneung happens only once each year, it would mean repeating a year of high school, too.
Haeryun Kang contributed to this story. For a behind-the-scenes look at reporting and life from East Asia, check out our Tumblr, Elise Goes East.