A team of speedrunners have annihilated Half-Life, crafting a speedrun that uses a strange teleportation glitch to finish the game in a little over six minutes.

The run was performed by members of the SourceRuns community, which is dedicated to hosting speedruns for games that use the GoldSrc (called “Gold Source”) or Source engine. It started as a project in 2016 after a new glitch was discovered. Half-Life uses the GoldSrc engine, which has a few interesting quirks that the runners used to blast through the game in 6 minutes and 26 seconds. The current world record for the Steam version of the game is 31m 25s 193ms by parklez. This run is “segmented” and performed by multiple runners, so it’s technically in a category unto itself. But it’s also one of the fastest runs, thanks to some strange occurrences in the GoldSrc engine.

Chief among these oddities takes place in the game’s console, where actions and scripts are run. Whenever players perform an input, it is placed in a queue before being run. Using a command called “wait” pauses the progress of that queue, which includes pausing level transitions. By forcing the console to wait, runners can cross level boundaries without immediately loading the next level. This allows them to move back through a level they were just in; when the new level loads, their position is offset and they start in a location different than the game intends when running normally. This allows players to load out of bounds or in specific locations, a trick they can use to skip through most of the game.

If you want a far more technical breakdown, you can watch the video above. One of the key glitches is called “save warping.” By loading a save during the wait period, runners can further manipulate their position. However, you can’t just warp to any map. If you warp to a map that isn’t connected to your current one, you spawn into the game unable to move. The trick is to “chain” warps together, creating a sort of ping-pong pathway through the game. The end result is a speedrun that starts normally and then slowly builds into a rapid fire Quantum Leap episode.