Let It Glow is an early-game objective in Rainbow Six Extraction.
Part of the 'Scouting Ahead' track in New York City's missions, it gives you the objective of making an enemy bioluminescent through a wall.
Trouble is, the game doesn't explain what this means, or how to achieve it. That said, chances are you'll play with this challenge active, and complete it without knowing how you did it.
This page explains how to make an enemy bioluminescent through a wall in Rainbow Six Extraction, and why it comes in handy.
If you're after more help, see our explainer on how to rescue MIA Operators in Rainbow Six Extraction.
How to make an enemy bioluminescent through a wall in Rainbow Six Extraction
Bioluminescence in Rainbow Six Extraction works by shining your flashlight on a destructible wall. If an enemy is behind the wall, then they will be visible.
Completing the objective on the face of it is rather simple, especially as your flashlight will always be active, and is shown wherever you aim with your weapon. In other words, there's no need to 'equip' any other features - the bioluminescence will occur automatically.
The only tricky part is finding an enemy behind a thin wall. With the game having a randomised nature, you might have to explore a few Hot-Zones before you come across a destructible wall with an enemy waiting behind it.
The built-in nature of the flashlight means you'll see it immediately, and should then instantly complete the objective.
The feature, once you discover it, is very handy. It essentially means you can see enemies - including nests - through walls for 'free'. As with Rainbow Six Siege, you can then shoot these enemies and take them by surprise. With a precision shot, you can defeat them with stealth kills, and not alert those nearby.
It even works across the room; as long as you can see the enemy through the wall with bioluminescence, they will be vulnerable.
The video at the top of this page shows this feature clearly, with a drone showing the locations of the enemies outside of bioluminescence, before taking them down with stealth through the wall itself.
Hopefully that makes completing the Let It Glow objective a little easier!
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