For this Fortnite challenge Doctor Slone asks you to get hold of three alien devices, then activate the countermeasure device under Corny Complex.
This challenge is actually split into two stages. To begin with, you will have to locate the alien devices, and then go and activate the countermeasure device.
Where to find alien devices in Fortnite
Alien devices take the form of purple orbs. There are three in all, and that's a good thing since that's the number of you will need to collect to complete the first part of this quest.
They are all located in the alien biomes that surround Corny Complex, so head there.
How to enter Corny Complex
Once you have recovered the three alien devices, you have to infiltrate the IO base at Corny Complex. More precisely, you will have to enter the main building -- the huge red barn.
This is Slone's base of operations against the alien invasion. There are several solutions to enter the base:
- Via the main entrance to the barn, where a flying saucer is parked.
- Via the underground passage to the right of the barn.
- From the silo next to the barn, which gives access to stairs.
Once in the basement of the IO base, head to the room at the back. There is a huge ball-shaped machine there. This is the countermeasure device.
Interact with it to place the orbs that you have collected, and then sit back and enjoy the XP!
Be mindful that Corny Complex is a very well-guarded place. Don't even think of going there unarmed, as the IO guards are tough enemies.
There's also Doctor Slone, who has the ability to multiply and do three times more damage to you.
Then there's enemy players to contend with, too...