And then he left to pursue a film career that has included the third-worst Spider-Man movie and first-worst film to ever be titled Valentine's Day. His void was filled by a character named Randy, and until we see the deleted eighth season episode "Randy Is Slowly Choked To Death By An Invisible Laughing Hand," I will never be able to forgive That '70s Show for what it did.

When a main character ends up departing and it wasn't pre-planned, shows scramble to put a Band-Aid on it. X-Files hadn't been interesting for two years by the time David Duchovny left, and filling his absence with Robert Patrick's steely gaze did nothing to make Season 8 of The X-Files seem like a bad spinoff of Season 2 of The X-Files.

20th Century Fox Television

Steve Carell leaving The Office gave us a performance by Will Ferrell that may as well have been replaced by Will Ferrell screaming, "Like me! I am THE FUNNY MAN!" at the camera for four episodes. Even The Andy Griffith Show tried to replace Don Knotts with Jack Burns. If you ever look at a grandparent and they have weird, silent horror painted across their face, they're not remembering the war or any past trauma. They're remembering Jack Burns on The Andy Griffith Show.

Even worse is when a main character refuses to give any kind of s**t for the remainder of the show's run. Jason Segel's performance in the last season of How I Met Your Mother is the acting equivalent of a second-grader counting down the minutes until the bell rings. The closest thing that I can compare it to is Harrison Ford in Return Of The Jedi. If Ford had been on set for just an hour longer, every take would be him walking over to George Lucas and spitting on him.

Lucasfilm

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In some cases, when a character leaves unexpectedly, the show can actually benefit from it. When Paul Schneider left Parks And Recreation at the end of the second season, the show became even better, mainly because the writers didn't have to wonder, "Should Paul give a slightly amused glance or a droll glance? Guess we'll leave it up to chance," at the end of every joke. Raymond Cruz, who plays Tuco in Breaking Bad, asked to leave the show way before the writers were through with him. And while it would've been entertaining to end every Season 2 episode of Breaking Bad with Tuco beating another one of his own henchmen to death, we may have never gotten Giancarlo Esposito's Gus Fring, who to this day is the greatest Lex Luthor in media history.

Sony Pictures Television

A setting can do more than just create worthwhile plot devices. It can carry a mood that feels unexplainable until you leave it behind. Nip/Tuck seemed like the kind of show that, even in its dullest moments, would never stop being something that your conservative great aunt would complain to you about. Its first four seasons are set in Miami, but it later moves to L.A., effectively changing it from "A sometimes interesting and often absurd look at plastic surgeons in Miami" to "A show set in L.A." Creating a show that's set in L.A. about the wacky people that live there is such a tired idea that the scripts should've grown bed sores. No amount of craziness can distract from the reality that your show is now based around the fact that, and I don't mean to get too edgy with this observation, some L.A. people are vain.

Warner Bros. Television

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If you look at comedy shows like Archer or Eastbound & Down, changes in location kept the shows fresh when, logically, they should've reached their "Sell by" date. Archer moves from New York City to Miami and eventually to Los Angeles, and Eastbound & Down goes through the redneck spectrum of Shelby, North Carolina; Mexico; Myrtle Beach, South Carolina; and Charlotte, North Carolina. In both cases, none of the transitions were simple "Same s**t, different time zone" deals.

Even The Walking Dead, which seems to move at a rate of six episodes per day, was able to take a shift from a farm to a prison and run with it. A show about people making distrustful glances at each other became the nasty, claustrophobic battlefield that it was always meant to be. And then it stagnated there too, because The Walking Dead never learns from its mistakes as much as it just adds more decapitations to them.

AMC Studios

Pacing is super important because it's often what makes a show an actual show and not just a collection of scenes that happen to all have Bryan Cranston in them. When the pacing of the show changes (whether it be the time being accelerated forward or the momentum of the show being altered), it's often a jarring, messy experience. When the writers of Rome were told, while working on the second season, that a thoughtful yet boob-filled look at history wasn't exactly putting new shoes on their kids' feet and that they were getting shut down, they rushed to fill the last few episodes of the second season with multiple seasons' worth of stories.

HBO/BBC

Thus, Rome became a clip show, kind of like how you never quite know what's going on with the day-to-day lives of the people you went to high school with as you meet them over the years at varying stages of their beard-length. In its final weeks, Rome was the guy who seems to have a new career every time you meet him at a bar, but it only seems that way because you haven't been in your hometown since 2011.

When shows base a majority of their stories around a single conflict and then suddenly remove that conflict, they can be sent spiraling through time. The Tudors was never going to be The Wire-level television, but goddamn did they do as much as they could with the "Are they gonna bone? And will they like it?" arc of hot Henry VIII and Anne Boleyn.

Showtime Networks

But when they killed Boleyn off, Henry VIII's narrative became not unlike the way that Seinfeld handled his girlfriends. "She chews too loud! And she can't sire me a son! What's the deal?" The plot that headed to Henry and Anne boning and hating each other at least gave the show a focus, and made the fast-forward through the Middle Ages tolerable. Without it, The Tudors, like Rome, seemed like a history-book reading assignment that you decided to just flip through, even when time was passing at a similar rate to the way it had in the pre-porking years.

However ...

Un-setting a show's internal clock can do great things for certain pieces of television. I hate to keep talking about how great Breaking Bad is three years after it ended, but, well, get used to it. I don't hate it. After more than two straight seasons of the chess game between Walter White and Gus Fring, Breaking Bad seemed to ignite rockets on its back, and it shot forward through a season of revelations, neo-Nazis, and f*****g Todd. The mix of time jumps and accelerated storytelling accentuates the notion that, even though we are finally seeing a Walter White that has slammed his giant nutsack on the table and announced, "Bring it!" to Albuquerque, we are also seeing him in an inescapable freefall.

Sony Pictures Television

Time jumps have also benefited shows like Boardwalk Empire. The way that time moves didn't necessarily change, but leaping a few years into the future makes everything seem more urgent. A show that tends to float through the Prohibition era suddenly becomes a countdown. And no matter how awesome Steve Buscemi's character is, history has shown that when Steve Buscemi dies, that m**********r gets it. Steve Buscemi death scenes should be treated like passing comets. Get out a lawn chair and tell your kids to go somewhere else if they don't like it. Something special is about to go down.

HBO

Sometimes people who will never write a word of a show's scripts or shoot a single scene will change the show forever. When some executive decides, "Eh," a show that was formerly a standout in a crowd of "He's a nerd, but she ... isn't" programs can plunge into irrelevancy. Don't get me wrong -- Twin Peaks was always a weird show, and I can't wait to see the batshit typhoon that it becomes when an older, stranger David Lynch brings it back in 2017. But it became significantly less intriguing when networks pressured Lynch to wrap up the show's main murder mystery in the middle of its second season. By effectively solving the murder of Laura Palmer, Twin Peaks transforms into a show about crazy small-town folk with nothing engaging to do.

CBS

Batman: The Animated Series was never a bad show, but it did become a vastly different one after the network decided that Robin needed to be in every single episode. Apparently, there's nothing that kids love more than to see their favorite superhero bombarded with puns from someone with a higher-pitched voice than he has. It was still a really good Batman show, but adding Robin meant taking away any chance that we'd see any more stories based around Batman confronting some kind of deep inner torment. Instead, we did get to see Batman and Robin beat the s**t out of way more mob henchmen, and the day that more punching stops making things better is the day that I wake up without a smile on my face and without a fist on my arm. In all things, one must punch.

Warner Bros. Animation

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Networks did right by The Munsters, though. If you've ever wanted to see what a soul looks like while it's dying, watch Joan Marshall's performance in the 14-minute unaired pilot for the show. She was eventually replaced, probably because she acts like showing even the slightest bit of enthusiasm would blow her up like the bus in Speed. Also, executives decided that the show needed to lose the color that made every actor look like they'd just been the victim of chemical warfare, and they replaced the original opening theme with a song that you know Herman Munster liked to f**k to. That is some werewolf baby-makin' music.

There's a sweet spot in Family Matters right after the producers of the show saw dollar bills raining from the sky above Jaleel White's head and right before Steve Urkel became the monster that devoured the whole thing. They knew that Steve was the breakout character and proceeded to put him in every frame of the thing. And while Family Matters would eventually become The Steve Urkel Show (And Don't You Dare Say Otherwise), there are a few seasons in the middle where it's clearly better than its biggest early-'90s rival, Full House, instead of just slightly better.

Warner Bros. Television

Supernatural and The X-Files both go through the same motions. At least Smallville has the allure of possibly seeing a Superman villain hint about one day being a bigger Superman villain. Supernatural works fine as the madcap adventures of two guys with better haircuts than me. But as soon as it tries to force its narrative into seeming like a grand, serious epic of rising magnitude, it loses everything that currently makes the show watchable. This fall, it will move on to its 12th season, and so far it's been five seasons of actual stuff and six seasons of producers hoping that the two leads don't audition for a Marvel movie.

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As long as they're well-written, sitcoms can go on forever. It's Always Sunny In Philadelphia doesn't follow the traditional TV show arc of "Used to be good. Now it's not." There are some seasons that are weaker than others, but even in its 11th season, it proves that a show that's seemingly going nowhere can be infinitely better than a show that declares a false finishing point at the beginning of every year. The people behind Sunny have a stranglehold on the concept of "Five drunk sociopaths that bicker," and they refuse to let go. And while it's not as glorious as Supernatural's "Some demon is here, and trust us, he's waaaaay worse than the last three" concept, at least it doesn't make me want to scream, "AM I ALIVE? IS THIS ALL THAT LIFE IS?" into my apartment.

Warner Bros. Television

Daniel has a blog where he writes things. I give it a B+.

Zoroastrianism used to be one of the biggest religions in the world, but their idea of heaven had a slight twist on it: to get there you'd have to cross a bridge. Sometimes rickety, sometimes wide and sturdy, if you fell off you'd go to the House of Lies for eternity. Fun! Not terrifying at all! This month, Jack, Dan, and Michael along with comedians Casey Jane Ellison and Ramin Nazer as they discuss their favorite afterlife scenarios from movies, sci-fi and lesser-known religions. Get your tickets here and we'll see you on the other side of the bridge!