It's the penultimate episode of The Walking Dead Season 4. And by the way folks, "penultimate" just means "next to last." It doesn't mean "super mega ultimate" as many people seem to think.
Super Mega Penultimate Spoilers Ahead!
We follow four different groups this week, and some of them finally make it to Terminus, the super mega ultimate refuge we've been hearing about all year.
Glenn and Maggie's groups combine and decide they have nothing better to do than check out Terminus. They finally arrive, and... the place looks deserted. Security seems to be pretty lax at this supposed sanctuary. They don't even have guards posted at the front gate. They just push the door open and walk right in. What's to keep any walkers from doing the same?