The door from Milliways opens onto a
high, vaulted room of polished marble. At least, it appears to be marble at first glance. Closer examination will show that the walls and floor are a little too smooth and the patterns in the stone are a little too regular to have come from any real mineral source.
At the other end of the room are a set of ridiculously tall double doors, standing half-open. Through those doors, one can see a glimpse of strange, high-tech-looking buildings, backed by a circuit-patterned sky.
"Welcome to Mainframe, guys."