(Head to the Museum Finishing Room to find the Landau siblings) "You receive a message from the Landua siblings. As expected, they contacted you because they want to ask for your help, just like everyone else. Unlike the others, however, these two deliberately set up a mystery for you -- They will only tell you what they need if you head to the Museum Finishing Room as they had requested.
Is this even the right attitude when you want to ask people for help? You don't quite know, since you were only born in the Herta Space station a short while ago -- but you must have gotten used to this random way of getting missions by now.
Head to the Belobog History and Culture Museum Finishing Room and listen to their request."

From the 1.3 update of Honkai: Star Rail. Part of the Slices of Life Before the Furnace Companion Mission Chapter.

2023.10.12 (1332)