"The Walking Dead" is back for the second half of its fifths season, and I have a review of tonight's episode coming up just as soon as I make use of this model airplane...

If the 2014 episodes of "The Walking Dead" offered occasional glimmers of optimism, and even chances for characters to smile — but also, yes, cannibalism — then the series begins 2015 in a more hopeless, if not outright nihilistic, place.

Eugene's talk of a cure was a sham. Beth is dead. Bob is dead. Noah brings Rick's group back to the gated community where his family was, only to find the place overrun by zombies. Michonne — more human than ever, and as a result more tired — suggests Eugene had the right idea about Washington being a potentially safer place, but the way things have been going lately, odds are they'll get there to find walkers in the Rose Garden, the Mall, the Reflecting Pool, and every other damn place.

"What Happened and What's Going On," written by Scott M. Gimple and directed by Greg Nicotero, is one of those periodic "Walking Dead" episodes that wants to remind us that there can't be a happy ending here. These episodes tend to put one or more characters — in this case, the doomed Tyreese — in a situation to wonder if they want to keep on living, and keep on fighting, even as it's all but asking the audience how much misery and pessimism they will abide in their weekly drama series. With this episode, the show kills off one of its most likable characters, puts its remaining heroes in a situation where no option seems like a good one, and then surrounds them with garish imagery like the field of severed zombie parts(*)

(*) Given that Rick ran into a truck carrying the other body parts, I wonder if we're heading into a story about whoever was responsible for chopping all these bodies up, or if it was just meant to be one more awful thing for them to confront on such a terrible day.

I found this one to be a mixed bag. On the one hand, both Chad L. Coleman and Tyler James Williams were terrific at playing the varying degrees of hopelessness that Tyreese and Noah were fighting at different points of the episode; when Tyreese told the Governor's ghost why he forgave Carol, it made me sad that the series was almost certainly about to lose Coleman's services. (From my notes as I watched the episode: "Oh, don't kill Tyreese, show.")

On the other, it's hard to pull off a long sequence where a character converses with hallucinations without it feeling self-indulgent, and I don't think this one cleared that bar, no matter how good Coleman was. In this case, the episode was also hamstrung by which dead characters could appear. Because Tyreese was a relatively new addition to the cast, Gimple couldn't dust off Shane or Lori, and some of the dead people he was closest to (his girlfriend, any of the people who were traveling with him and Sasha when they found the prison) would have little to no resonance for us, so we wound up with a few characters (Bob, Beth) whose deaths were so recent that they barely feel gone, two (the girls) who look notably older than when they died, and one (the Governor) whom I'd be glad to never see again, especially since Martin the Termite made an effective enough devil on the shoulder so as to not need another villain to taunt the dying man. (Also, the show's "we're going to finally tell you this guy's backstory right before we kill him" move has never been one of its more graceful.)

Mostly, though, "What Happened and What's Going On" was a reminder of how difficult it is to sustain the narrative of this series without simply wallowing in misery. This really is a world without much hope, and the show hasn't flinched from that, but the characters need some sense of direction(**) or immediate conflict, for the show to avoid feeling like something where everyone on screen would be better off just blowing their brains out.

(**) Speaking of direction, the notion of the characters finally leaving Georgia after all these years was glossed over much too quickly, as was the journey itself. I'm not saying I needed even a single episode devoted to getting from Atlanta to Richmond, but given the way the show has established the great difficulty of traversing any kind of distance, perhaps a montage of them getting into various skirmishes, having to take detours, etc., might have been in order.

Gimple likes to periodically do episodes like this, or "Clear," or "The Grove," that pause and let one or more regulars confront just how bad the world has become and the unfathomable depths to which they have sunk as human beings. Those previous two were more effective than this one, in part because they weren't the first episodes back after a hiatus, in part because they had a cleaner and more powerful narrative and visual style. (All the flourishes here — the time-fractured prologue, the home movies, Tyreese imagining news reports that sound like BBC Radio describing the adventures of Rick's group — were more distracting than anything else.)

I suspect whatever direction this half-season is heading will be made clear within the next few weeks, but I'm disappointed Tyreese won't be a part of that journey.

Before we go to the comments, it's time once again to explain how this blog's No Spoiler rule applies to this show:

1. No talking about the previews for the next episode.

2. No talking about anything else you know about upcoming episodes from other sources — and, yes, that includes anything Gimple and Kirkman have said in interviews.

3. No talking about anything that's happened in the comic that hasn't happened in the TV show yet. (Or anything that's been revealed, like character backstory and motivation.) As with "Game of Thrones," the goal is to treat "The Walking Dead" TV show as exactly that, and not as an excuse for endless comparisons with the comics. If you want to talk about the comics, feel free to start up a discussion thread on our message boards.

What did everybody else think?

Alan Sepinwall may be reached at sepinwall@hitfix.com

Alan Sepinwall has been reviewing television since the mid-'90s, first for Tony Soprano's hometown paper, The Star-Ledger, and now for HitFix. His new book, "TV (The Book)" about the 100 greatest shows of all time, is available now. He can be reached at sepinwall@hitfix.com