I think it would be a great way (for us) to end the show if some convoy--well armed and supplied, ppl in uniform,etc, shows up at Alexandria with some new piece of equipment--something like an LRAD say. They turn it on and the heads of every walker in a mile range explodes.
or better, someone developed a anti walker head exploding App for a smart phone (android of course)-the convoy ppl begin handing out new phones with the app installed to everyone in ALex. Rick of course will not take one with some speech on how there (the convoy ppl) "way of living isn't right, fake and ready to fall apart,etc,etc"--more Grimes Bullshit
then the leaders turns to Rick-who just got down with another emo filled rage event-and asks, "why the hell have you all been living like this? we've been waiting for you to come North where everything is under control. We came to you instead."
or something like that
just a total anti climatic end to the whole shebang-one that entirely deflates all of the rabid TWD fans out there