As three-dimensional beings, it was almost impossible to cross the barrier into a higher-dimensional world.
Just as two-dimensional beings could not perceive the existence of a three-dimensional world, without scientific theory or special technological means, all they could observe were the projections cast by three-dimensional objects onto paper under a desk lamp or another light source. Or, at the instant the two came into tangential contact, they might observe a series of "strange properties" produced on the contact surface—physical laws incomprehensible to two-dimensional beings.
And all of it was merely the result of "interference."
Even if they perceived their existence, from the standpoint of lower-dimensional beings, reversing the interference exerted by higher-dimensional space upon lower-dimensional space was almost impossible.
In that respect alone, the existence of Four-Dimensional Space Fragments was somewhat similar to that of Z Particles.
Only, their existence was far more complicated.
They were not some kind of matter existing in four-dimensional space. Rather, they were space itself.
Therefore, in theory, crossing this barrier was impossible.
No physical attack could have any effect on it. Even if someone brought over a megaton-yield nuclear bomb and razed the ruins to the ground, it would not shake it in the slightest.
However, that did not mean Lu Zhou had no way forward.
The ruins' internal space had been sliced into countless small pieces by Four-Dimensional Space Fragments. All the passageways here remained topologically continuous and unchanged. Their altered positions were merely distortions caused by the fragments' interference with three-dimensional space, mixing the tunnels together like scrambled puzzle pieces.
The reason he could not cross the barrier before him was simply because the "door" was not here. This inaccessible space in front of him was like a puzzle piece forcibly removed from a complete picture and tossed into some inconspicuous corner.