Bronya returned to the Overworld just like that. The Silvermane Guards guarding the engine core recognized the Supreme Guardian's heir and knew she had been missing for several days. Now that she had been found, they treated her with the utmost care and escorted her back to the Overworld.
The first thing Bronya did upon returning to the Overworld was to report back to her mother.
Inside Qlipoth Fort:
Chapter 31