If Flatland's Model Is Correct...

Visualizing the First ' Second ' Third ' and (hinting at) the Forth dimensions, Flatland (story) describes an existence, where, all the dimensions interact with each other (however limited). If this expression is believed, then, would it be too farfetched to imagine the 3Dness in the universe is the 4th dimension seeping into our 3D "plane" ?

Would it be soo difficult to imagine a galaxy or nebula as, simply, the fragments of a 4D thing "bleeding" through ?

The theory would be, the cluster of things we see, in space, is, actually, part of a larger thing we CAN'T see... And, only, bits of it can penetrate the 3rd dimension, but, because it's one thing, it has to stay together, like a nebula or galaxy. 

Maybe the galaxies ' nebulas ' rogue objects are, even, all, 4D biological cells (???)