Blimey. If you ever needed an excuse to not be a vicious online troll, this is it. Also, don't be a shitty person and, for heaven's sake, protect the bees.

The episode begins with DCI Karin Parke (Kelly Macdonald) giving testimony in a British court. It all started on the 15th of May, she says.

The 15th of May is the day British journalist Jo Powers is branded a pariah by the public over her controversial denigration of a disability rights activist who has died by suicide. Everyone's tweeting their hatred for Powers and someone has even taken the trouble to send her a cake iced with the words "Fucking Bitch."

It truly is a rotten day for the hate-mongering hack. She's later found with her throat slashed. According to her husband, who is in the hospital with injuries from the attack, she mutilated herself.

Parks doesn't buy his story, but Blue, her new shadow (a sort of tech forensics officer played by Faye Marsay), feels like something is amiss. They investigate the teacher who sent the cake to Powers and learn that it was all part of a game inspired by a new #deathto hashtag. The teacher feels no culpability in Powers' death.

Rapper Tusk is also on the public's shit list. His popularity plummets after he mocks a young fan on a talk show. Soon, he, too, is mutilating himself after being invaded by an ADI, or drone insect, which is a futuristic bee alternative that can pollinate flowers. Tusk dies after being put in an MRI machine — its magnets rip the drone insect out of his eye socket. A similar drone insect is found in Powers' brain.

What exactly are these ADIs? They're part of a government project called Swarm and created by a company called Granular. They replicate in hives all over Britain for environmental purposes and have replaced bees. Rasmus, Granular's top tech, is shocked to learn that the ADI found in Power's brain has been hacked locally.

Parke and Blue join forces with a government agent named Sean (Benedict Wong). It's just in time, too: Blue has done some digging and discovers that the #deathto hashtag is building an audience. It's part of a "Game of Consequence," in which the top person mentioned alongside the hashtag is "eliminated" after 5 p.m. each day. The game resets at midnight.

That day's target is Clara Meades, a young hippie who is being blasted online after posting a selfie that shows her pissing on a war memorial. The team leaps into action and extracts Clara, placing her in a safe house in the country. (Giving her some sort of protective helmet to keep the drone insect from burrowing into her brain might have made sense, too, guys.)

Blue is in touch with Rasmus to track the ADIs in the area. It's not just one drone insect pursuing Clara, though. To Rasmus' horror, every single hive breaks up and heads to the safe house. Despite Parke and Blue's best efforts, one slips through the bathroom fan and flies up Clara's nose, causing her to have a seizure and die.

News of the deaths and their connection to the hashtag goes public, but people aren't put off. Instead, they're gleefully targeting unpopular personalities like Chancellor Tom Pickering. In a meeting with Sean, Pickering demands to shut down the internet. Then, he suggests leaking documents that would likely move someone else to the top of the kill list. Sean's plan is to blow up the hives, but his military demo proves that this isn't possible. After being detonated, the drone insects just come back with a fury. Blue also learns that the government and Sean's agency have been using the ADIs in the past to spy on citizens. They're built with facial-recognition technology, which is why they're so adept at singling out their targets.

Parke and fellow officer Nick Shelton throw their energy into interviewing past Granular employees who may be the culprits behind the ADI hacking. One woman is Tess, a former employee who slashed her wrists after being bullied on social media.

'It was like having a weather system turn against me," she tells Parke of being vilified online for accusing a man, later found to have a learning disability, of harassing her. Her flatmate, Garrett, was the one who rescued her.

Garrett Scholes turns out to be another former Granular employee. Blue discovers his 98-page manifesto embedded within an ADI. He wants to hold people like Tusk and Meade accountable for their actions, hence the #deathto hashtag he's created. It seems strange that a man who saw his friend Tess battle cyber-bullies would suddenly side with trolls, but no matter. Blue tracks down the location of his hideout and the team is off.

The hideout is empty, but turns up what appears to be Scholes' toolkit. Rasmus pulls it up and discovers a list of 387,000 people. It's a list of everyone who used the hashtag, including the cake-buying teacher and Nick Shelton, who couldn't resist tweeting "#deathto Garrett Scholes." Nice going, Nick. It all dawns on Parke: Powers, Tusk, and Meade were just the bait. Scholes is actually targeting the trolls.

And then, Sean has to go and push a button to deactivate the ADIs. It doesn't actually deactivate them, though. It sends them all into attack mode. Liza the teacher and Nick are soon being stalked by swarms of drone insects.

Scholes wasn't even in Britain this whole time. He changes his appearance, dumps his equipment in the water, and trots off looking like any other tourist exploring South America.

The rest plays out in the present day, where Parke is finishing up her testimony. Hundreds of trolls died in the drone insect attack and the public is seething. Blue, Parke tells the court, blamed herself for her role in the case. Four months later, she left behind a suicide note at a beach.

Just kidding! She's actually stalking Scholes, Hannibal Lecter-style, near the Andes. Parke receives an anonymous text that reads "got him." The DCI smiles, then deletes the message. The episode ends with Blue following Scholes home. Yas queen!

And just like that, Black Mirror season 3 is a wrap. We've seen soldiers being brainwashed, cheaters getting blackmailed by hackers, and Instagram likes running amok. Now, we've got trolls being taken out and the suggestion that cyberbullies who hide behind avatars are worse than the people they vilify online. Do you agree? Did you hate it? Just remember to play nice in the comments. You never know what might happen.