This guide details the "Just Like the Good Old Days" main mission in S.T.A.L.K.E.R. 2: Heart of Chornobyl. The mission's preceding quest varies depending on player choices in "Wishful Thinking," either "To the Last Drop of Blood" or "Law and Order," both culminating in an escape from SIRCAA.
Key Objectives
- Talk to Professor Lodochka: Locate Professor Lodochka at Quite's Camp on Wild Island. Expect an immediate encounter with mercenaries, clearly marked on your map. Equip yourself well, as further combat is anticipated. Eliminating these mercenaries completes this initial objective.

- (Optional) Activate the Ventilation System: This side objective unlocks after dealing with the mercenaries. Locate a fuse (marked on your map), then proceed to the marked engineering rooms to the north. Be prepared for an invisible enemy within the shelter. Restore power to the ventilation system using the fuse. Completing this simplifies the main mission.

- Find the Source of the Signal: This section requires robust weaponry. Enter the cave near the water, navigate westward through the caverns, utilizing a broken pipe to reach higher levels. Locate the emitter near a large cone-shaped spire. An invisible enemy awaits on your return journey. Finally, report back to Professor Lodochka to complete the mission, unlocking "Hornet's Nest" as the next main quest.
This walkthrough provides a comprehensive guide to navigating this challenging mission in S.T.A.L.K.E.R. 2. Remember to prepare adequately for combat encounters.