Strider and his Monolith squad recently regained their freedom from the Monolith and want to seek shelter before they are discovered and attacked by other stalkers due to them wearing Monolith uniforms.
You can recruit Strider and his squad into either Freedom or Duty by talking to Loki and Shulga respectively. However one will need to earn the trust of one of the leaders for them to send recruiters.
One only needs to have a friendly reputation with one of the factions to earn the leaders trust, which is essentially one side mission that allows the player to choose which faction to side with. To earn a leader's trust while attempting to obtain the A Man of Balance achievement, 2 of these 3 quests must be completed favoring them: Turning in Flint to them, assisting Yar at Kopachi (Freedom), or getting them to dispatch a squad to guard the scientist's bunker.
Alternatively if you have the Diplomat achievement then you can earn either leader’s trust just by turning in Flint to them, and reviving a few injured stalkers in the field. The best strategy here is to find a fire fight between Duty and Freedom members, run between them reviving anyone who falls down, then return to the station, save and try turning in Flint to both leaders. You can still help Yar if your reputation need more of a boost.
It should be noted that there is a bug that results in Monolith Survivors opening fire upon the recruiters. It is not known what causes this.
UPDATE: to correct the above behavior edit resources/configs.db. Search for relations until you find a text chart that describes the relations between each faction, find the value for Monolith and Freedom (usually -5000 for the bug to occur) change the value to 0. (Taken from this post)
Side missions possible
- General Tachenko's PDA given to either Shulga or Loki
- Morgan's PDA given to either Shulga or Loki
- Tell about Flint's true identity to either Shulga or Loki
- Refer either Freedom or Duty to guard the scientist's bunker after Black's squad leaves to ambush the player in the Jupiter factory complex.
- Assist Yar at Kopachi (Freedom)
- Diplomat achievement (Raises players reputation with all factions)