I suspect that the horn is the teenage girl, trapped in a car and honking the horn for help, not knowing about the Zombie Cattle Drive-- or just being stupid.
Unless Enid is a plant for a threat yet to come, it would make no sense for her to blow the horn--she's experienced in the ZA world enough to know that sound attracts zombies. Blowing a horn might draw an army of zombies to the car before any humans could reach her.
You thought the teenager was Enid, but Jesse's angry son (who will learn how to use a gun) shoots to the top of the ticking time bomb outliers of season 6, along with Nicholas, Deanna's son Spencer, and possibly Morgan. Yes, Morgan. I can see him going along the same lines as his statement in "Clear"--
"'Cause if you got something good, that just means that there's someone who wants to take it."
--to make the point that he has gone from being that person building arms to defend the prison, to the kind of person he was fighting against--again the Governor's world view:
"In this life now, you kill or you die, or you die and you kill"
Rick might not have heads in fish tanks, or set zombies after victims tied to a chair, but he's too willing to kill to protect "his" world. Others have lost as much, but are not taking the road that ends with absolute state of "war," and seeing everyone as a threat.
Adding to that, his new stand against letting anyone else in (the conversation with Daryl) saying they need to take care of themselves is cold-blooded--particularly after he was saved and/or taken in by:
- Morgan in the pilot.
- Hershel at the Greene farm.
- Saved by Carol when he was seconds away from death at Terminus.
- Given shelter by Father Gabriel.
- Shelter provided by ASZ.
Anyway, great start to the season. Massive Zombie Horde. Lots of interesting character stuff
Yes--it will definitely fuel the external threats to come. Daryl and Morgan might end up being the odd men out, with a possible, final rift separating Daryl from Carol.
Daryl is now walking the same path as season 3 Andrea and season 5 Tyreese about not wanting see people die / trying to find peaceful resolutions. That is such the opposite of Rick that I would not be surprised to see Daryl leave to form another community.
I did wonder why they didn't try to destroy the Zombies trapped in the quarry. Build some fertilizer bombs, drive them off the edge. They could have destroyed thousands of them.
Good question.