Any fan of television will tell you: a series finale is a tricky thing to handle. There needs to be a reverence for the show's past while also wrapping up any loose storylines. Of course, this is only true if the series wasn’t canceled abruptly. Unplanned series finales often leave fans screaming over cliffhangers and missed opportunities. If a show is allowed to run its natural course, however, then the series finale is key. It is the the swan song for the series.

What should a series finale be? It has to wrap up any long-running storylines, give satisfying ends to the characters, make sense with the tone of the show, and feel like a good bookend to where things started. There are often twists in a finale, usually in regard to a character’s future or how the show finally ends. These twists can make a series finale or it can break them. Whether it makes or breaks the series, the most memorable ones definitely have a way of sticking around in the cultural consciousness.

Needless to say, what we’re about recount may give the most dedicated viewer some serious flashbacks. These twists may have very well ruined the entire series or left audiences with a warm fuzzy feeling in the end. It’s time to take a long look back at those plot twists that had audiences frothing at the mouth or them sobbing into their tissues.

These are 14 Series Finale Twists That Hurt Their TV Shows (And 11 That Saved Them).

HURT: Mom Loses Her Life (How I Met Your Mother)

Ted and Tracy with the yellow umbrella in How I Met Your Mother

It took almost a decade for Ted Mosby’s (Josh Radnor) children to learn how he actually met their mother. During the final season, we saw the circumstances that led to him and the Mother (Cristin Milioti) meeting after Barney (Neil Patrick Harris) and Robin’s (Cobie Smulders) wedding. After all that build-up, all that we’ve seen over nine seasons to get to the moment, did Ted and Tracy get to have that happily ever after?

No! Instead, she loses her life to a disease. All that build-up for Ted to finally meet the kids’ mother and she turns out to be gone, with Ted's whole story being an excuse to date "Aunt Robin." It’s one of the most frustrating twists in television history. 

HURT: Lumberjack Dexter (Dexter)

Dexter with a beard in the final scene of the original series.

In its last seasons, Dexter was definitely the show on a decline. Long before Inhumans or Iron Fist felt showrunner Scott Buck’s poison touch, he led Dexter to its end. Nothing could quite live up to the epic disappointment that was this series finale. With everything collapsing around him, it looked like Dexter (Michael C. Hall) drove himself into a hurricane to end his own life.

Rather than his lover Hannah (Yvonne Strahovski) and son Harrison in Argentina, he decided to let them all think he had perished. Instead, he ended up working as a lumberjack in Oregon. It's an absurd, meaningless ending and totally anticlimactic. It feels like a twist for twist's sake.

HURT: Spencer’s Evil Twin (Pretty Little Liars)

Spencer and Alex Drake on Pretty Little Liars

Pretty Little Liars was pretty much a wild show from start to finish. Didn’t anyone everyone tired of all the As running around? There was, naturally, an Uber A, also known as A.D. In the most soap operatic move from the show, this Uber A was Spencer’s (Troian Bellisario) heretofore unknown identical twin sister. What did said identical twin sister want? She wanted to be Spencer.

It turned into the plot of Single White Female at the end, with the added absurdity of Spencer's evil twin having a cartoonish Cockney accent.

SAVED: Don's Coca-Cola ad (Mad Men)  

Jon Hamm as Don Draper in Mad Men Finale

Sometimes, a show’s ending doesn’t have to be happy or uplifting. It just has to make sense for where the character is going. We didn’t know where Don Draper (Jon Hamm) would end up after Mad Man finished, but it felt like the series would end with Don finding some sort of spiritual enlightenment after his years wasted on an empty pursuit.

Except, no, this didn’t happen. Don, instead, used his enlightenment to make a Coca-Cola ad. It’s a twist that made a lot of sense for the character. 

HURT: Sherlock has a Sister (Sherlock)

Eurus looking hopeful in Sherlock

We don’t know if Sherlock is officially ended. After the mess that was its fourth season, it certainly makes sense that it should just end. One of the weirdest twists to come out of the final episode was the secret sister, Eurus (Sian Brooke) that Sherlock (Benedict Cumberbatch) never knew he had. She was a criminal genius who rivaled both her brothers, and had secretly been pulling strings behind the scene this entire time.

Even the show's star Martin Freeman (who plays Watson) expressed disinterest in returning to the show.

SAVED: House Faked His Own ing (House)

House had a lot of ups and downs during its eight-season run on Fox. Usually, these were mainly House’s (Hugh Laurie) fault due his general misanthropy and addiction. In the series finale, it looked like all caught up with him when he apparently perished in a fire. What happened, however, was that the genius faked his own end in order to spend time with best friend, Wilson (Robert Sean Leonard), who had a malignant form of cancer.

It was considered to be one of the best twists in 2012. It also made sense to the character. The only way House could actually be happy was if he utterly left himself behind.

HURT: Everyone Ends Up In Jail (Seinfeld)

Seinfeld Finale

For most of its nine-season run, Seinfeld dominated the airwaves. The quirky characters and the endless quotable moments made it must-see TV for a lot of people. Needless to say, the finale was going to be huge. Instead, however, it was mostly just baffling. The gang ends up on trial for breaking a Good Samaritan law when not getting involved to help stop a mugging. They then go on trial for it and are surprisingly convicted.

The final moment for the “show about nothing” was Jerry (Jerry Seinfeld) playing to an audience of convicts. It was absurd, but not in a good way.

SAVED: Colleen Wing Is Iron Fist (Iron Fist)

Iron Fist had a bad first season, but the second season showed a lot of potential. There was a definite increase in quality, and season 3 seemed promising with the twist that Colleen (Jessica Henwick) would become the new Iron Fist. It was definitely one of the best things that the show did and makes us sad we won’t see more from it.

One of the more surprising elements was that Colleen’s ancestor, a pirate, was also the first female Iron Fist.

HURT: Dan is Gossip Girl (Gossip Girl)

Who is Gossip Girl? Throughout the six-season run of the series, the question constantly lingered in the background. Who was the mysterious host of the site that dished on the young elite of New York City? Many theories were written on the identity. Finally, audiences learned that Dan (Penn Badgley) was, in fact, Gossip Girl. It was apparently a seven-year love letter to Serena (Blake Lively) and their friends.

Sure, Dan. We’ll just pretend that the reveal doesn’t throw into question previously established canon. It still vexes the Gossip Girl fans to this very day.

SAVED: Winston's Eviction Prank (New Girl)

New Girl series finale balcony

New Girl lasted a lot longer than most thought it would. Over the course of seven seasons, the kooky bunch of friends who populated the loft were known for their epic pranks. Nothing quite topped the one in the series finale.

It turns out that Winston (Lamorne Morris) made everyone think they were being evicted. This remains perfectly in line with the character and the show. It was also a prank that inspired growth as it allowed Nick (Jake Johnson) and Jess (Zooey Deschanel) to officially move out the loft.