The Walking Dead2010

[last lines]

Rick Grimes:
[in a flashback] I know this sounds insane, but this is an insane world. We have to come for them before they come for us. It's that simple.

[in the present, we see the herd of walkers walking according to plan, when an unexpected horn starts blaring out in the distance]

Heath:
What the hell is happening?

Glenn Rhee:
It's a horn or something. It's pulling the back half off the road. Oh, God.

Michonne:
Whatever that is it's far. It sounds like it's coming from...

Rick Grimes:
Home.

[the camera shows from a bird's-eye view the hundreds of walkers heading in the direction of Alexandria]