Back in 2011, YouTuber Duelies filmed themselves jet packing to the top of a far-off tower in Halo: Reach. It was an impressive feat — the building was in the background of the Exodus level and therefore not meant to be scaled — but the Halo trickster thought players could probably one-up the achievement. What if someone could reach the top without using a jetpack?

So began one of Halo: Reach’s most long-standing “launch” challenges, which dared players to catch tremendous air and, hopefully, land on a white roof alive and intact. It’s much harder than it sounds. Aaron Sekela, a Halo: Reach fan who is a part of a collective known as Termacious Trickocity, has been chasing this white whale for years now, on and off.

Sekela admittedly almost lost hope. The Halo-launching veteran says it was the most stressful trick he’s ever attempted — and he’s accomplished a great deal in Halo games already.

“There were times when I was trying it thinking to myself this isn’t really worth it,” Sekela told Polygon. “But at that point I sunk so much time into it, I would have been wasted time if I didn’t complete it at that point. That was my driving force towards the end, just get it done so I don’t ever have to play on this level again.”

Part of what made the challenge so difficult was the complicated set-up. Just putting all the pieces into place takes eight hours, Sekela says — and that’s if everything goes according to plan.

You need to get two warthog vehicles in places they were never meant to be. You need to push boxes across the map, a small detail that nonetheless takes a whole hour on its own. All the while, Halo: Reach is still humming in the background, assuming that you’re trying to play through the actual level. This means contending with checkpoints that can thwart progress. There are four of them in the relevant portion of the level, which means there are four different opportunities for the game to throw launching attempts in the trash.

“So if your Warthog blew up before a checkpoint, you have to revert back multiple hours,” Sekela said. “Or if a box fell off an edge and wasn’t retrievable, we had to revert back again until we got everything where we needed it to be.”

That’s just to get everything into place. The actual jump requires some delicate maneuvering, too. Once players catapult themselves from the starting tower, they have to contend with what is known as a “fall timer.” You can only fall for a limited amount of time in Halo: Reach before the game outright kills you. The game also activates Insta-death if you get too high on any given map, or if you get too low. Meaning, reaching the Halo: Reach tower wasn’t just about hitting something with enough force to go the distance — it’s also about nailing the perfect angle, from one tower to the next.

Assuming you get that correctly, there’s still one final piece of the puzzle here. The launch requires force and speed, which means that it’s very easy to land on the final spot and die. After hours of set-up, there’s still no guarantee you’ll survive the fall.

Sekela estimates that he’s poured nearly one thousand hours into the Halo: Reach challenge, from figuring out the set-up to actually landing it. And this year, he finally did it. He still can’t quite believe it.

“Midway through the launch I said, ‘this looks like a good one,’” Sekela recalls. Once his character’s body hit the warthog on the other side and lived, he remembers gasping. He flipped out and started screaming, “I did it! I did it!”

“I was shaking, it was such a surreal moment,” Sekela says. “Even days later I still couldn’t believe it.”

You can view the trick in the video at the top of this post, starting from 25:53 to 26:36. It’s a part of a larger collection of clips showcasing all manner of impressive tricks and jumps. From 17:22 to 17:34, for example, the Halo group manages to get into what they call the “Truth Room,” which is a hidden locale in Halo 3’s Crows Nest level that houses the game’s main villain. Players had managed to get into the room years ago, but it was empty. The question then became: Can you stand in there while Truth is also present? For this, Termacious Trickocity had to figure out when the game loaded Truth into the room, even if it wasn’t actually visible to the player.

“We couldn’t get in the room early and just wait for the certain moment where he appears because the players would get pulled out of the room when we progressed through the level,” Sekela said.

“In order to get him to appear we clipped into the room at a different point in the mission right before he appears in it.”

It sounds simpler than it actually is. Sekela says that the trick requires multiple sequence breaks and specialized techniques that are difficult to explain, but the group promises that they’ll release a full tutorial in the near future.

“It’s the only time you can see the Truth biped in game,” Sekela notes. However, the collective found that Truth isn’t actually a solid entity in this room, and will disappear if you get too close or shoot him. Trickocity discovered that if you use Active Camo to go invisible, however, Truth won’t notice you — so you can get close and get a good look at him.

Now that Termacious Trickocity has cleared one of their oldest challenges in the series, they’re looking toward a wider backlog of Halo-related tricks that are currently considered impossible.

“I have faith we can knock a few of them down still,” Sekela said. “We’re hoping with Halo: Reach coming to PC in a few months that we can make some new discoveries ... hopefully we can continue to whittle down the list.”