Every previous season of Showtime's Dexter has been positively packed with tension and season seven is promising to continue that trend.  For those of you who haven't caught up with the show, we'll save the spoilers until after the jump.  Let's just say that Dexter (Michael C. Hall) was in a tight spot at the end of season six.  While this happens nearly every season, the current predicament hits pretty close to home.  Unfortunately, the new trailer is super spoilery, so only go ahead and hit the jump if that doesn't bother you.  Dexter, also starring Jennifer Carpenter, Lauren Velez, David Zayas, C.S. Lee and show newcomers Yvonne Strahovski, Ray Stevenson and Jason Gedrick, returns Sunday, September 30th at 9PM on Showtime.  Hit the jump to see the bloody new trailer.Last chance to turn away from this spoilery new trailer for season seven of Dexter.  You've been warned:dexter-season-7-poster