It appeared that Adam Ondra was going to just waltz up the Dawn Wall—the 3,000-foot rock climb on the steepest, longest section of El Capitan in California’s Yosemite National Park.

The 23-year-old Czech rock climber, who is a World Champion sport climber and widely considered the best rock climber in the world, had been absolutely crushing the Dawn Wall since he began his bid to achieve its second free ascent at 1:30 a.m. on Monday, November 14. That morning, climbing through the dark and into the dawn, Ondra successfully completed the first nine pitches—in other words, the first nine rope lengths, each roughly a hundred feet—of the climb, which towers at 32 pitches in total.

On November 15, he climbed the next four pitches, each one extremely difficult and dangerous.

The initial success that Ondra achieved over these first two days represents an extraordinary achievement when placed in the context of what it took Tommy Caldwell and Kevin Jorgeson, two American rock climbers, to achieve the first ascent of the Dawn Wall.

The Dawn Wall, with a difficulty rating of 5.14d on the Yosemite Decimal System, is considered the hardest big wall (anything that typically takes climbers more than one day to complete) free climb in the world.

Caldwell and Jorgeson spent a lot of time, spread over the course of at least seven years, working to climb the Dawn Wall. It was a period during which they rehearsed moves and installed a bare minimum of protection bolts, required for safety. Finally, over 19 continuous days in January 2015, Caldwell and Jorgeson achieved the first free ascent of the route—meaning they climbed each and every pitch in its entirety without a fall. Their historic ascent became a media sensation, turning a spotlight onto a relatively small sport that also tends to be rather complicated for laypeople to understand.

Caldwell is considered Yosemite’s best rock climber—he’s dedicated the last two decades of his life to pioneering new free climbs on El Capitan. He considers the Dawn Wall to be, thus far, his crowning achievement in Yosemite.

Ondra, meanwhile, had only first arrived in Yosemite a few weeks before he started his attempt. Prior to this visit, he had little experience in trad climbing, which is more complicated and can be more dangerous than sport climbing, Ondra’s forte. He had also never before climbed in Yosemite, which is notorious for its extremely technical and idiosyncratic style of movement.

That he’d been able to successfully free climb the first 13 pitches during his first two days, considering his background, certainly bolstered his reputation for being one of the best rock climbers in the world, if not the best.

Then, Ondra arrived at pitch 14.

Pitch 14, with a rating of 5.14d, is the first crux, or most difficult section, of the entire route.

After a rest day on November 16, during which he and his climbing partner, Pavel Blazek—a fellow Czech rock climber who is there to support Ondra as a belayer—lounged around in their portaledge camps 1,200 feet above the ground, Ondra steeled himself for pitch 14, an improbable, horizontal traverse left across one of the most sheer sections of El Capitan.

The first six or so feet of pitch 14 contain, perhaps, the most difficult sequence of moves on the entire 3,000-foot rock climb.

Here, on the afternoon of November 17, Ondra fell. He returned to the belay (the start of the pitch), pulled his rope, and tried again.

Another fall. Frustrated, Ondra once again returned to the belay for another attempt.

View Images Adam Ondra struggles on pitches 14 and 15 of the Dawn Wall. Photograph by Pavel Blažek

Six attempts later, Ondra still could not make it past this section of pitch 14.

By now, it was dark and Ondra was climbing by headlamp. On his seventh try, he actually made it past this initial stretch of difficulty. He was elated, but focused. He continued climbing slowly across the blank, tenuous wall. He was only a few moves away from reaching the next belay—the end point of pitch 14—when his foot slipped, and he fell again.

“It was heartbreaking,” Ondra said. “Pretty frustrating night. I can’t complain about the weather conditions. I felt, physically, really good. But today, these moves, which never felt hard for me before, turned out to be really hard.”

Ondra is best known for his difficult ascents on limestone sport routes, which are typically 30 to 50 degrees past vertical. He’s also known for his climbing speed; he’s able to move up impossible-looking cliffs at a quick pace, climbing without any hesitation and absolutely just flowing up the walls.

The unique style of climbing in Yosemite, however, rewards patience and perfection over speed.

“It’s really hard for me to get into this mind-set,” a frustrated Ondra admitted during a phone interview from his portaledge camp. “Normally, it’s more efficient to climb fast. But here, you’re always on your feet, you’re not exerting full-body tension, and for me that’s when it gets hard to focus.”

Ondra has plans to try pitch 14 again today, November 18.

After that, he hopes to do pitch 15—another 5.14d and the last of the two hardest pitches on the route.

If he can get through pitch 14 and 15 today, Ondra stands a good chance at achieving his goal of a second free ascent of the Dawn Wall. After pitch 15, indeed, 17 more pitches remain—however, they’re all relatively easier than what Ondra has already climbed.

Still, anything could happen. His fingertip skin could become too torn to continue, or his body could just give in to the overall fatigue of spending multiple days living on the side of a 3,000-foot big wall.

National Geographic Adventure spoke to Ondra both before and after his heartbreaking battle with pitch 14. Stay tuned for more updates on Ondra’s progress over the next few days.

Before pitch 14:

How do you feel so far?

The first two days were big days with a lot of climbing. But hopefully I managed to rest all the fatigue away yesterday. I was afraid my finger skin would be in really bad shape after this marathon, but now it feels OK. It’s not 100 percent, but it’s acceptable. As long as it stays windy and cold, hopefully it should work out on the crux pitches—pitches 14 and 15.

What’s the biggest fall you’ve taken so far?

When I did my initial ground-up attempt I took a 12-meter fall on pitch 6 because I ripped out a bunch of gear.

Of the first 13 pitches that you’ve done, which one was the scariest?

Definitely pitch 10. Not necessarily because it’s dangerous, though. On this push, I haven’t really been scared about taking big falls. But I have been scared about making mistakes. Any fear about falling has been erased out of my mind on this attempt because I’ve been so focused on the climbing.

Pitch 10 is one of the hardest—a really long, tiring layback crack. [A layback is a climbing maneuver in which you grab onto the side of a vertical crack with your hands and press your feet onto the opposite side of the crack to create opposition.] I was right at the end of the pitch, about to clip into the anchors, when my foot slipped. I still don’t understand what happened. It happened right at the worst time, too, because the sun was on the pitch, and now there was water seeping out of the crack.

I tried pitch 10 again, and five of the footholds were wet. I just forced myself to deal with it, and somehow, it worked and I didn’t fall.

What are you eating up there?

For lunch today, we had mashed potatoes with chickpeas and some curry. For breakfast, mostly oatmeal. For dinner, it’s usually more mashed potatoes.

What has surprised you most so far?

At first, I was surprised by how insecure the climbing style is. It’s possible to fall anywhere, even on the easier pitches. That’s why you have to be focused on every single pitch, not make a mistake. Every mistake costs you in lost skin, and you get more tired.

After pitch 14:

How are you?

Not very good. I did not even send pitch 14.

What happened?

I don’t know. It was heartbreaking. Pretty frustrating night. I can’t complain about the weather conditions. I felt, physically, really good. But today, these moves, which never felt hard for me before, turned out to be really hard.

I just couldn’t trust my feet, and the more careful I was, the more inefficient I was climbing. It’s really hard for me to get into this mind-set. Normally, it’s more efficient to climb fast. But here, you’re always on your feet, you’re not exerting full-body tension, and for me that’s when it gets hard to focus.

Are you feeling any pressure to succeed?

Yes, that’s definitely one hard part. I just have to somehow deal with it, or try to get rid of it.