Duo was across the bridge in no time and traveling into the room and jumping a bit down the stairs to the other set that Toph had built, though he didn't really distinguish that. He saw stairs, and he didn't even see them as the stone they were. Reality and his memory were blurred together. From his perspective? He was inside of the moon base.

And it was honestly awfully strange that there were stairs at all! Welp... Can't stop to think about that! He ran up the stairs and out the door that lead to the roof top platform.