The latest missile firing comes amid heightened tensions on the peninsula, following wide international condemnation for the North's January nuclear test.
Google's AlphaGo program has already won the best-of-five match against Lee Sedol. But Sedol now has ensured it won't be a clean sweep by getting a victory in on game four.
Lee Sedol has lost three games in a row to Google's AlphaGo program, which means the program has officially defeated the human. Lee said the pressure was intense, and he felt "powerless."
"They were neck-and-neck for its entirety, in a game filled with complex fighting," according to a recap. The five-game match will continue through the weekend.
This year's war games between the U.S. and South Korea are the largest ever. In response, North Korea's Kim Jong Un threatened to unleash a "preemptive nuclear strike of justice."
Opposition legislators have now spoken for some 150 hours straight, holding up a bill that would give new surveillance powers to South Korea's spy agency.
In the weeks between North Korea's nuclear test and rocket launch, 4,000 new American troops have arrived in South Korea. They're still adjusting to challenges, both big and small.
The protest, organized by Amnesty International, featured virtual demonstrators. But concerns about freedom of speech and assembly in South Korea are real.