Harold Halibut

Chapter 1.3

1. Agora Arcade - Talk with Tommy in Gertrude's bier zone (Listen to gossip and talk to everyone else in Agora Arcade for a few other achievements).

2. After you are done at Agora Arcade, go to Energy District - listen to the conversation between Chris and Brigitte and then talk to Cyrus here.

3. Go to Lab District - remove graffiti and talk to Mareaux about Cyrus's message.

4. Go back to Agora Arcade - Talk to Tommy, finish dialogues and watch cutscenes.

5. Go back to Lab District - talk to Mareaux.

Achievement should unlock. No need to go back and forth to Cyrus and Mareaux more times.

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100% complete walkthrough guide:
(Timestamps are in YouTube pinned comment)

I missed this the first time i played through so i had to go back for it and this time made notes.

from the start menu load up chapter 1.3.

wake up and exit your room, you'll automatically speak to mareaux and go through the microscope sequence. (receive the task to go to tommys.)

go to the arcade section and look at the rock in the shop window

meet with tommy in gertrudes bier zone and go through the conversation. (receive the task to check on brigitte)

return to mareaux and update her.

go to the energy section and go through the dialogue with harold watching brigitte and chris talking.

return to tommy and go through the conversation ending with him changing the sign and the rock going missing.

return to mareaux to update her essentially ending the task.

i then went to give cyrus her message and did the 3D printer electricution sequence.

i finally went back to Mareaux one last time, on the way the lights went out for the end of day.
Speaking to her this time returned Cyrus's message and popped the achievement.

Hope this helps.

During Chapter 1, Mareaux will ask you to retrieve a blue rock from the arcade district. After doing some tasks, the rock will have been stolen! Before doing anything else, immediately head back to the lab and keep talking with Mareaux until this achievement pops!