Greased Lightning is a secret achievement in Halo Infinite. It is worth 10 Gamerscore points. The goal is to complete the Movement Yard in under 25 seconds.
Greased Lightning achievement in Halo Infinite
There are several achievements to unlock in Halo Infinite, but there are a few secrets that can be discovered if you look hard enough. One of them is actually found in Spartan Academy Tutorial Mode of the game, and it will reward you with the achievement called “Greased Lightning”.
How to Get Halo Infinite Secret Achievement – Greased Lightning
To unlock the Halo Infinite secret achievement Greased Lightning, you have to run an obstacle course in under 25 seconds. This achievement can be obtained during the tutorial.
Here is how to get the Halo Infinite secret achievement Greased Lightning. Check out the exact steps below:
Complete the movement course in the tutorial.
The first requirement in order to unlock the Greased Lightning secret achievement is to complete the Movement Course. Complete this first in order to start the secret achievement course, which has no timer, so just relax and complete it leisurely. After reaching the goal, all you need to do is go back to the beginning of the course and start it again.
Ask AI to start course again with timer.
Hold the confirm button on the pedestal to tell the AI to close the door and try again. When it opens, the movement course will be available again but this time there will be a timer when you try to exit the doorway.
Do a fresh run.
There are some dummies you’ll need to fight along the way, but they’ll be gone by the time you get back to the starting point. So get rid of them and move along.
How to Easily Beat the 25 Second Timer to Get Greased Lightning Achievement
Sprint! Jump onto sandbags and pallet
- The first thing to remember when trying to beat this course with a 25 second timer is to sprint immediately when coming out the doorway. Next, you will need to jump onto the sandbags nearby the right wall and then jump onto the pallets, just enough to stand on them.
Jump and climb over 
Dash and crouch into the hole
- For the next step, look up and try to jump over the wall in front of you. Climb up and then sprint towards a hole on the wall with a downwards arrow above it. Crouch down and you will be dropped below it.
Sprint through tunnel 
Avoid dummies
- Sprint again through the short tunnel until you see the exit. If you see those dummies, just maneuver around and do not bother destroying them it will only waste your precious seconds.
Jump on sandbags Climb over small ledge
- When you reach outside the tunnel, go straight for the two sandbags and jump on top of them. Now turn around and look up. There is a yellow railing just above you but at the corner, there is a small ledge you can climb over with. Reach that and climb over to go to the next flight of stairs.
Climb up stairs and railings 
Reach goal!
- By the time you get here, you can just jump over the railings and easily reach the goal. You have now beaten the timed course just below 25 seconds. Some players have achieved 20-21 seconds in one run.
- After you have reached the goal, there will be an achievement that will pop up on the screen. It will say that you have completed the Greased Lightning Achievement. Congratulations!
Halo Infinite launches December 8, 2021 for Xbox One, Xbox Series X/S, and PC.
Check out our other articles related to Halo Infinite below:
- Halo Infinite All Gear and Equipment – Location, Upgrades, and How to Use Them
- Is Halo Infinite Campaign on Game Pass? All You Need to Know About Halo Infinite on Xbox Game Pass
- Halo Infinite Campaign Length – How Long to Beat and Missions List
- Halo Infinite All Bosses Guide – How to Defeat Every Boss in the Campaign
Also check out this awesome video by Pfhorbear on how to get the Greased Lightning Secret Achievement: