[You may use the palace as you please. If you decide that you must leave this world, I will allow your exit. You only need to tell me when the time comes.]
That was what Hades said. It made Atlas doubt if he'd have to make another perilous journey to come back, but that was a matter to consider when it came time for him to return.
At the moment, Atlas was walking the halls of the palace. He chose not to immediately leave the Underworld for obvious reasons, but that didn't mean he was standing still.
As he walked those halls, he found that the servants of the palace weren't any ordinary skeletal beings. They were capable of speech and thought like living humans. The only difference was their appearance.
When he approached them, they mostly avoided him. He was accompanied by a skeletal butler who was watching over his movements, but that didn't make them any friendlier.