You didn't miss out on jack.
Basically, the writers needed to kill off a character because they have too many of them that are ultimately going no where and decided to devote a whole episode on writing one off with some artsy hallucinations thrown in. Once again a character that we've seen able to hold their own against hordes of these annoying walkers is suddenly taken down by one random walker that appears out of thin air when they turn around.
When a character has outlived their usefulness in the story, they get the axe in the dumbest way possible.
- Dale, turns around and SURPRISE, there's a walker!
- Merle, sniping in a nice secluded area, SURPRISE, there's a walker!
- Andrea, like Tyreese, able to hold her own against hordes and hordes of walkers, taken down by a single walker!
- Bob, you capable mother ****er, of course the surprise random underwater walker goes for you and not the Priest that is somehow brand new to this world! So much for outliving everyone you encounter!
And now, we have Tyreese. We've seen him get jumped by dozens of walkers and beat them with nothing but a hammer. We've seen him forced outside of a shack with dozens of walkers RIGHT outside the door with nothing but his bare hands and come out unscathed. BUT a little, child walker, who we saw behind a closed shut door a few seconds earlier, is behind Tyreese on in no time flat. He doesn't hear it walking or doing the typical walker throat gurgling until it's right behind him like some horror film super villain. Not only does it happen to the poor guy once, it happens twice in the same episode!
It's formulaic at this point. Character isn't useful to story, writer creates some forced situation that kills said character off, usually utilizing a single, random walker.
