Original sentence: The stories could have continued as a series indefintely, were it not for Blish setting the end of the Universe in 4004 AD (the chronology in early editions of They Shall have Stars differed somewhat from the later reprints, a hint that this may not have been planned by Blish at the beginning of the series)
Edited sentence: Aside from the fact that it contains the end of the universe, A Clash Of Cymbals contains staggeringly bad physics, of an order of magnitude more silly than anything else anywhere.The stories were pure space opera, and could have continued as a series indefintely, were it not for Blish setting the end of the Universe in 4004 AD (the chronology in early editions of They Shall have Stars differed somewhat from the later reprints, showing that this had not been planned by Blish at the beginning of the series).The whole thing lurches from silliness to oddity until it is rescued by the end of the universe; it is the treatment of this which I believe to be unique in science fiction, and which raises book and series into genius