Once the final script is "closed" (finished), you will receive the achievement under the "The Memories We Share" category and 5 Stellar Jades.
To "close" all the scripts and unlock the achievement, you need to find and interact with three specific left by a "mysterious playwright" in the Janus Polis area. Locations of the Scripts
All three scripts are located within the map. Look for golden interaction sparkles on the ground or on walls: The First Script (The Hero's Beginning):
Found near the steps leading to the main temple. This script concludes the story of the "Empire." How to Unlock the Achievement
Near the Temple of Janus or the northern plaza area.
This "write-up" likely refers to the hidden achievement (Driving the Empire's Script) in Honkai: Star Rail , found in the Amphoreus region (introduced in Version 3.0) .
Interact with the script found on a stone bench or near the architectural pillars by the main walkway. It discusses the "birth of a hero." The Second Script (The Middle Conflict): Location: In the Residential District area (Central-East).
You must read the dialogue for all three locations.