'I finally watched 20-year-old Netflix show but shocking twist at the end broke me'

I recently started watching the original series of Dexter and one episode has plunged me into a state of mourning. Okay, I'm being melodramatic but it did break me. Any fan of Dexter likely knows what I'm talking about but if you haven't watched the show yet and want to avoid spoilers, turn back now.

You've been warned. I am, of course, talking about the harrowing twist at the end of the season four finale episode, The Getaway. Dexter originally aired between 2006 and 2013, and followed the exploits of serial-killer-with-a-conscience, Dexter Morgan, a crime scene blood spatter analyst for the Miami Metro Police Department, who juggles his desire to kill people with his day-to-day responsibilities masquerading as a "normal" person.

Dexter, played by Michael C Hall, is led to believe he's a sociopath and "monster" by his adoptive father, police officer Harry Morgan, who found him as a three-year-old child, sitting in his mother's blood after she'd been brutally murdered in front of him.

Harry spots Dexter has a penchant for violence and is somewhat lacking in the emotions and feelings department and, instead of getting him in with a grade A child psychologist to work through his very obvious trauma, he teaches him "the code".

Dexter wants to kill people but only if they meet Harry's code - they must be murderers themselves. Over the years, he completes ritualistic slayings of countless violent criminals who appear to have escaped the justice system.

As the show progresses, Dexter's actions continue to catch up with him and, at times, he spoils evidence to ensure a perpetrator escapes arrest so he has the pleasure of killing them.

This is none more apparent than in season four, where we meet Arthur 'the Trinity Killer' Mitchell, played by a brilliantly menacing John Lithgow. The actor was so effective, he bagged a Golden Globe award for his turn as the chilling serial killer.

Now, in a show that's decades old, some spoilers have been unavoidable - for example, I'm not expecting to be thrilled by the much despised ending, and I knew the main villain in the first season was Dexter's long-lost brother.

But I didn't expect what season four had in store for viewers.

By this point in the show, Dexter is married to Rita - played with sweet and endearing charm by the wonderful Julie Benz.

Dexter was drawn to Rita as a ploy to support his "nice, normal guy" image but, over time, we see there is genuine care and affection for her. I loved Rita and hoped her continued influence on Dexter would prove to be a positive thing for him.

But Dexter's obsession with the Trinity Killer proved to be her undoing.

After a cat-and-mouse game which sees Dexter come up with a pseudonym to get close to Arthur Mitchell and his family, it all starts to unravel.

Mitchell soon clocks Dexter isn't who he's been claiming to be and shows up at his place of work, mulling over images of his own crime scenes without a care in the world.

Dexter sends Rita and their son away on a belated honeymoon to ensure she's safe from the sadistic killer.

After some serious tension, Dexter seemingly prevails - he traps Arthur on his trusty table and kills him, tossing his hacked up body parts into the ocean.

We've seen this scene before - Dexter is nothing if not consistent when it comes to how he completes his crimes.

When he returns home, he discovers a voicemail message from Rita saying she'd forgotten her passport so had to return home to get it.

He calls her, but her phone rings in their house. Dexter walks into the bathroom and there, in a harrowing full circle moment, is his son sitting in a pool of his mother's blood.

Rita is laying dead in the bathtub, the water crimson - one of the Trinity Killer's trademarks.

I was hysterical.

The show did an excellent job of convincing us Dexter had won and got the better of the Trinity Killer.

As the show is years old, I have nobody to talk to about this gut punch of a twist so I scoured the internet and saw it's still a widely discussed episode to this day.

I know it's not an episode I'll ever forget, no matter what direction the show - and its subsequent spin-offs - takes from here.