Just a few hours remain before President Trump's 8 p.m. ET deadline for Iran to reopen the Strait of Hormuz or face what he characterized as the total destruction of the country's civilization.

• Trump, posting on Truth Social today: "A whole civilization will die tonight, never to be brought back again. I don't want that to happen, but it probably will."
• Trump previously threatened to destroy Iran's bridges and power plants, and he's mentioned other civilian targets, like oil and water infrastructure.

Progress has been made over the past 24 hours in talks between the U.S. and Iran, according to several sources, Axios' Barak Ravid reports.

• A U.S. official said the thinking in the White House has shifted from "can we get there?" to "can we get there by 8 o'clock tonight?"
• Negotiations are expected to continue right up until Trump's deadline, sources said.

Reaching a ceasefire deal by then still looks like a long shot.

• Sources say the key challenges are meeting Iran's demand for a strong guarantee that the U.S. and Israel won't resume the war after a pause, and the slow pace of responses from Iranian leadership.

U.S. markets are dipping slightly on the prospect of a massive bombing campaign targeting civilian infrastructure across Iran and the unknowable fallout.

• The S&P 500 is down nearly 0.8% as of midafternoon.

Some Iranians are fleeing to perceived safety in the country's north, AP reports.

• A Tehran-based designer, speaking anonymously for her safety: "If there is no electricity, there is no water, because the water pressure in Tehran is low and all buildings have electric water pumps. You can't cook either."

Get the latest.

Anthropic is limiting access to a preview version of its new Mythos AI model to a handpicked group of companies over concerns about its ability to find and exploit cybersecurity flaws, Axios' Sam Sabin reports.

👩‍💻 Anthropic's Logan Graham tells Axios that Mythos Preview is "extremely autonomous," with the skills of an advanced security researcher.

• Mythos Preview can find "thousands of vulnerabilities" that even the most advanced bug hunter would struggle to spot, Graham said.
• Unlike past models, it can also exploit those vulnerabilities.

🐞 Anthropic says that in testing, Mythos Preview found bugs in "every major operating system and web browser."

• Mythos Preview successfully reproduced vulnerabilities and created proof of concepts to exploit them on its first attempt in over 80% of cases.

🐧 For example: Mythos Preview found several flaws in the Linux kernel — found in most of the world's servers — and autonomously chained them together in a way that would let a hacker take complete control of any machine running Linux systems.

Graham tells Axios: "It's very clear to us that we need to talk publicly about this."

• Go deeper ... Get Axios Future of Cybersecurity.

1. 🇰🇵 Speculation is rising that Kim Jong-un's teenage daughter, Kim Ju-ae, has been chosen to succeed him as North Korea's leader, The New York Times reports. Gift link.
2. 🧳 Delta is raising checked bag fees by $10 or more, the airline announced today. That follows similar moves by United and JetBlue as the Iran war drives up jet fuel costs. Go deeper.
3. 🏈 Activist and former 49ers QB Colin Kaepernick is writing a memoir, "The Perilous Fight," due out Sept. 15. That's about a decade after he began kneeling during the national anthem to protest police violence and racial inequality.

Kaepernick, in a statement: "People saw the moment. But they didn't see the years that made it possible: the questions about who I was; the injustices I could no longer ignore; the voices of those who came before me that I carried into that stadium." Go deeper.

Images from Artemis II's lunar flyby are coming in — and they're absolute stunners.

• Above, Earth sets behind the Moon, with Australia and Oceania visible.
• It's a modern version of "Earthrise," an iconic photo snapped by Apollo 8's Bill Anders on Christmas Eve nearly 60 years ago.

🚀 🌖 ☀️ Below, the Moon blocked the Sun during a solar eclipse from the crew's POV.

More flyby pics.