Thirty-four years ago, Stephen King sat down and typed the following line: ''The man in black fled across the desert, and the gunslinger followed.'' As the ENTERTAINMENT WEEKLY columnist recalls, ''That's probably the best single line that I ever wrote and maybe it deserved a book. I'm not sure it deserved seven of them.'' Nonetheless, here we are, greeting the publication of Dark Tower VII: The Dark Tower, ''a whopper'' that King also insists is the end of gunslinger Roland Deschain's saga. At least for now. After all, this is a man who told this magazine two years ago that he would retire after finishing Dark Tower. Now he admits there's a brand-new novel sitting on his shelf: ''I'm looking at it right now and that's where it's going to stay for the time being.'' So, is he retired or not? ''I was deeply sad to finish with these books, and I had a period of real creative depression, to the point where I told people I was going to quit...[but] I can't be held responsible for anything I said in the course of the last two years.'' That, Constant Readers, is a no.