Mystery of the islands

Prime knows how to unlock the code-locked door in [ Volkhov AAA site] in Jupiter. Recently, the bizarre anomaly appeared in the Zone; it uprooted large chunks of earth, which are now levitating above the ground. Rumor is, the decoders necessary to unlock that door can be found on those flying islands.
== Walkthrough ==
=== Obtaining decoders from the islands ===
The islands are present in the following locations:
* Zaton - main walkthrough: Mystery of the islands/Zaton
* Jupiter - main walkthrough: Mystery of the islands/Jupiter
* Eastern Pripyat - main walkthrough: Mystery of the islands/Eastern Pripyat
* Swamps - main walkthrough: Mystery of the islands/Swamps
* Cordon - main walkthrough: Mystery of the islands/Cordon. Also leads to Huckster's loot.
* Yantar - main walkthrough: Mystery of the islands/Yantar.
* Red Forest - main walkthrough: Mystery of the islands/Red Forest.
* Generators - main walkthrough: Mystery of the islands/Generators.
Each time, you'll have to jump the islands bottom to top, and then solve a teleport puzzle sequence, with Prime giving you vague hints. Some teleports are invisible and have to be found based on Prime's hints. You practically have to read devs' minds to do that, so the guides are provided below. Some teleports are simply timed, so you have to stand still and wait a certain amount of time before getting tossed through the location (5-15-60 seconds, usually).
After going though the teleport sequence, you'll end up on the final island, surrounded by several artifacts (random Tier 2-4 modificates). There's also a One-digit decoder which can be hard to see and is the real goal of your quest. Walk while holding F, and make sure you picked it up! You'll get a PDA update when you do.
Picking up the decoder also spawns a small group of Splinters underneath the final island.
Once you get the decoder and leave the location, the islands disappear from it.
=== Talk to Prime ===
After getting all 8 decoders and completing Liberation of the Slavik the Bullfinch's squad, head over to Zaton and speak to Prime.
Prime says that one number is missing, but the islands on Zaton were arranged into the shape resembling either 6 or 9. He will need 22-24 hours (random) to decipher the code.
Wait for a day and return to Prime. He will tell you the code: 141592653.
=== Code-locked door ===
Travel to Jupiter and go to [ Volkhov AAA site]. Find the code-locked door underground, and enter the code you got from Prime. After unlocking the door, 3 groups of karliks (6 mutants each) will spawn behind your back, in the building above the bunker, and in the bunker itself.
Proceed to the bunker. On the lower level, you can find breakable boxes with random ammo. On the upper level, you can find huge amount of ammo and weapons, including the "Poltergeist" flamethrower.
You also find the rucksack with a note inside, saying that the author of the note wants to reward you with several unique objects. Pick it up; the door behind you will unlock. After a few seconds, you'll be suddenly teleported back into the bunker, starting the puzzle from Cartographer. It takes you to the final island in Hospital with a ton of unique artifacts, along with a rucksack with 20 (!) RPO-A launchers where the decoder would normally be. Here's the full route (starting from 6:51). Note: do not drop down from the final island immediately. There's also a bonus stash ahead.
After landing outside of the map, you will need some form of teleport to exit the map.
== After the quest ==
On the final island, you find the Sunshine artifact. The recipe for this artifact is sold by Informant for 500000RU, but it's fake - you can't cook it. If you bought this recipe, Informant will message you once you found the real Sunshine. After that, you can sell it to him for 2000000RU in his one-time cyclic task, earning the achievement Sunlight Giver.
== Notes ==
* You might want to bring a Grav-suit if you plan on taking all 20 RPO-A launchers back with you as they alone are 110kg, not to mention all of the artifacts, rucksacks, and other loot along the way. It would also be good practice to stash the loot from the Volkhov AA site somewhere in Jupiter before teleporting to the Hospital.
== Bugs ==
* The artifacts can fall off of the final island when loaded in. Since the bonus stash takes you outside of the map and it is difficult or impossible to get out of bounds again after picking up artifacts that have fallen within normal map boundaries, just reload your autosave so that you can grab all of them on the island.
* It's been reported that the decoders can be destroyed when going through the Portal in Limansk if you have any with you. (need someone else to confirm)