“Try to Reach Where Mem is and Rescue Mem” is a task in the Grove area during the “Wherefore Are the Wise Silent” quest in HSR.
This quest is part of the Trailblaze Mission “Light Slips the Gate, Shadow Greets the Thorn” in Honkai: Star Rail.
In this objective, you must reach out to Mem and rescue Mem in “Murmuring Woods” Grove of Epiphany, an area on Amphoreus.
Rescue Mem In HSR For Trailblaze Mission
To start searching for Mem, you should interact with the book on the side and Perform a Miracle to listen to Mem Voice. Then, walk across the hallway to the stairs, and on the way, you can obtain Janus’ divine speed blessings.
You should walk up the stairs and interact with the book to Perform Miracle again to listen to Mem. With Mem’s voice, you will know her proximity.
Just the side of the book, there is a Miracle Orb, which you must engage. To do that, you need to click the bottom right button and invert the illuminated area into the other space-time.

Also, you need to activate the Shrine of Prayers. Now hop on to the Golden Bough of Vows and get to the lower level.
Again, you need to find Golden Bough of Vows and get to the lower level. And there you will see Mem and Trianne surrounded by magical beasts.

Once you reach the Mem location, you must defeat the magical beasts surrounding Mem, leading you to the next task: “Pick the remaining fires with the Golden Bough of Vow.”
As you advance through the objective, you will face the black-robed swordmaster at the end. Defeating the boss is essential to completing the third Tralibizer mission in Honkai Star Rail.