Although we had relocated underground, the Second Research Institute was currently upside down.
The moment we stepped through the institute's doors, the direction of gravity would reverse, sending us falling upward, even though that was actually the direction of the moon's gravity.
"Ready?"
"Ooh! Ooh!"
Mono had changed into a white Cyber Bunnygirl Combat Suit, but she clung to my arm and cheered like a monkey.
"Then let's head out."
There was no path outside the door, but "above" us, we could see something like an underground plain. The space inside the moon was unexpectedly vast. Without Earth's mass, its density was much lower, leaving enormous expanses of empty space.
Mono and I leaped through the doorway arm in arm. After an instant of weightlessness, we fell "upward," but quickly adjusted to the new direction of gravity before landing.
Crash-!
The moment our feet touched down, the entire surface collapsed with a roar, sending us plunging deeper.
"You've got to be kidding me!"
"The Lunar Core's geology is too fragile! Hold on tight!"
"I-my combat suit has this!"
Bang-
Mono's bunnygirl Battle Dress suddenly expanded as though it had been inflated from within, turning her into a plump Michelin Man shape that concealed every contour of her body. Aldebaran had used this very trick to escape Xiao Xi's yo-yo restraints.
In that form, Mono hugged me and adjusted her position to serve as my human cushion as we crashed onto the next layer of ground. Thanks to the inflatable padding, the ground finally stayed intact...
"Phew? Are we stable? Did we survive?"
Holding me, Mono asked those questions and deflated her suit, leaving me lying on top of her.
"We couldn't have died anyway. The moon's gravity is only one-sixth of Earth's. Even a collapse wouldn't make the fall fatal.