Season finales can be a difficult craft to master, even for the best TV shows. They’re often about finding the best way to round out the year’s main plot points, typically in climactic style, while teacoming storylines for the next season to tantalize viewers. A major plot twist or signpost towards the show’s overall conclusion doesn’t go amiss, either, especially for adrenaline-inducing thriller series. Too often, however, season finales don’t quite hit their mark. Either they aim big but overplay their hand, or they simply fail to live up to their billing as the climax of multi-episode plotlines.

In the very worst cases, season finales can send an entire show completely off the rails, by doing irreparable damage to beloved characters, or setting up storylines that move a series in completely the wrong direction. This list isn’t just about episodes that happen to be season (or even series) finales. If it were, then the season ending of The Crown, and some painfully bad Simpsons episodes, would likely make the cut. Instead, we’re examining how specific season finales effectively ruined previously great shows almost single-handedly.

6 House – Season 7

"Moving On"

House remains one of the best TV shows of the 21st century, with Hugh Laurie’s incomparable central performance as the titular misanthropic medic redefining what it means to be a protagonist in a serial drama. Season 7 of House wasn’t the show’s best, but it still had plenty to redeem it. Even the disappointing end to Dr. Gregory House’s relationship with the love of his life, Lisa Cuddy, was handled sensitively, as painful as it was. That is, until House drove his friend and colleague James Wilson’s Chevrolet Corvette straight through Cuddy’s living room.

If only Gregory House hadn’t done something so utterly senseless and destructive in the season 7 finale, the show’s final season might have had the chance to rediscover what was best about it.

If this shocking moment was definitive proof that House couldn’t live without Cuddy, then it was also a clear demonstration that we couldn’t live with this version of the title character anymore. House season 8 was a shadow of what the show had once been, with Laurie’s lead character no longer funny, and just plain sad. If only Gregory House hadn’t done something so utterly senseless and destructive in the season 7 finale, the show’s final season might have had the chance to rediscover what was best about it. Alas, we’ll never know.

5 Skins – Series 4

"Everyone"

Seminal British teen drama series Skins was always a messy affair, with its purposely inexperienced writers’ team dreaming up different kinds of decadent excess to live vicariously through its characters in each episode. What’s more, the show had already made a habit of inserting daring plot twists into its season finales before it reached series 4. There was the sudden car accident at the end of Skins series 1, for instance, and the drug overdose to end the show’s second season. Yet, the series 4 finale was quite simply beyond the pale.

It was virtually impossible to invest emotional energy into any Skins character in series 5 and 6, with the knowledge that the show’s writers were capable of the abomination that ended series 4. The bizarre turn of events that saw a psychiatric doctor who’d previously played no part in the series bring Kaya Scodelario’s Effy Stonem under his control, before beating her boyfriend to death, was only made more absurd by the season’s final scene.

Jack O’Connell’s Skins character James Cook seemingly beat the psychiatrist senseless, although we weren’t even treated to that act of teenage vigilante justice, as the credits rolled just as the beating started. In light of such a ridiculous season finale, the mafia car chase in the environs of a Moroccan villa that began Skins season 6 was par for the course. Skins was never a very realistic portrayal of life as a British high-schooler, but from its season 4 ending onwards, the show became more infuriating than entertaining.

4 House Of Cards – Season 3

"Chapter 39"

When it started back in 2013, House of Cards was an early landmark in the streaming age, and a yardstick by which all other Netflix original series would be measured thereafter. The story of murderous, machiavellian Frank Underwood navigating his way to the top of the US state worked so well precisely because it was the personal mission of a politician to maneuver his way into the big time, by any means necessary.

But once Underwood reached the top of the tree, becoming President of the United States at the end of House of Cards season 2, his efforts to manipulate the environment around him purely on the basis of individual self-interest no longer made any sense. It’s believable to imagine Frank’s sinister methods working on the level of local or even national politics, but watching him employ the same maneuvers in the field of global geopolitics reduced House of Cards to the level of a cheap political soap opera.

The episode was strangely preoccupied with getting rid of the one redeeming feature of Frank Underwood’s depraved Chief of Staff, Doug Stamper.

Like Underwood himself, the show had ideas above its station, and its shortcomings were grievously exposed by this fictional presidency. A scene in the House of Cards season 3 finale that depicted Frank having a tiff in the Oval Office with his wife Claire, played by Robin Wright, about whether the presidency belonged to both of them equally, as though it were part of their marriage, rang particularly hollow.

Even worse, the episode was strangely preoccupied with getting rid of the one redeeming feature of Frank Underwood’s depraved Chief of Staff, Doug Stamper. Around half its runtime was devoted to Doug tracking down, kidnapping, and killing Rachel Posner. He apparently thought about letting her go, but House of Cards ultimately decided that it shouldn’t give any of its characters anything to live for. The show descended into a procession of one grisly cover-up killing after another in its fourth and fifth seasons, with this season 3 finale having marked the point of no return.

3 The Blacklist – Season 8

"Konets"

Along with his mentorship of bodyguard The Blacklist should have ended the moment it did so in its season 8 finale. The extended sequence of Liz’s life flashing before her eyes felt like a final goodbye for the entire show, in which case it would have made more sense.

As a season finale, though, Liz’s death was a gut-punch too many, that stripped Red of much of his appeal as a character, and robbed The Blacklist of one of its main strengths. Viewers spent the months after The Blacklist season 8 ended wondering what the show would do without Liz Keen. They were right to wonder, as things went downhill fast from this point on, with increasingly absurd plotlines reinforcing the sense that the heart had been ripped out of the show.

2 How I Met Your Mother – Season 7

"The Magician's Code – Part 2”

How I Met Your Mother’s series finale is among the most hated in TV history, but it wasn’t actually the episode that killed the show. In fact, the ending to HIMYM season 7, a two-parter entitled “The Magician’s Code”, was the moment the show completely lost its mojo. While most of the double-episode worked fine, it finished with a monumental twist too far, a habit that would become a trademark of the show’s disappointing final seasons.

Immediately after showing Barney Stinson’s proposal to his girlfriend Quinn, the episode jumped forward to a scene at Barney’s wedding, in which it was revealed that he was marrying Robin Scherbatsky instead. This moment was actually the real low-point of the Robin-Ted-Barney love triangle, as Barney had already broken up with Robin once, and he genuinely seemed happy with Quinn.

It felt as though How I Met Your Mother was just messing us around for the sake of it, something the series proceeded to do throughout seasons 8 and 9. Barney’s character arc was arguably the one opportunity the show’s creators, writers and showrunners, Carter Bays and Craig Thomas, had to write an ending for a story, rather than writing a story solely for its ending. Sadly, they blew it, with disastrous consequences for the final years of How I Met Your Mother.

1 Game of Thrones – Season 7

"The Dragon and the Wolf"

Although it wasn’t the worst episode in the entirety of Game of Thrones, “The Dragon and the Wolf” was probably the point at which we could say definitively that the show’s best days were behind it. The scene in which Game of Thrones’ sneakiest schemer Petyr "Littlefinger" Baelish was tried and executed by the Stark sisters reflected the series at its crudest, with jarring elements of exposition and a damp squib of a climax.

Seasons 7 and 8 of Game of Thrones were the only ones not directly based on the novels of George R.R. Martin.

On the other hand, the Night King’s spectacular destruction of the Wall at Eastwatch with the help of Viserion, a dragon he’d apparently slain in the previous episode, took things too far in the other direction. It seemed as though the dragon had been brought back to life specifically to play the part of a deus ex machina in this crucial scene, undermining the internal logic of the fantasy elements in the series.

Raising dragons back from the dead essentially suggested that almost anything could happen in Game of Thrones. This penultimate season finale setup a dramatic decline in quality throughout its eighth and final season.