Return of the Symbols.
Isaac and Darth were led to the room with a portal. The room was on the second floor, and it was the most heavily guarded room by far.
They had to prove their identity first before being able to enter that room. Apparently, the residents in Moon City aren't allowed to go to the portal because they will get wiped out from existence just from touching it.
Proving their identity was easy and quick.
They had scanning devices, which let the machine tell how long that person has spent time in Moon City and if he was born there.
The scanner showed mere 3 hours and that they weren't a resident of Moon City, but there was also the fact that multiple cameras captured them entering the Moon City through the gate.
A professional-looking man stopped in front of the room and whispered a few words towards the Guards, who simply nodded and opened the door.
Isaac and Darth entered the room behind the man and saw a door on the other side of the room.