Spiderhead summary and ending explained

Spiderhead is a Netflix sci-fi thriller film about a group of convicts at a secluded research facility being experimented on by a cold-hearted warden for his own personal gain. The film is now streaming on Netflix.

Warning: This article contains heavy spoilers

Plot summary

A man in an observation room is asked to agree to a trial of sorts. He is then administered a drug and the man conducting the experiment tells a few jokes. The man begins to laugh uncontrollably at these tame jokes.

He’s not even able to stop himself when they switch to stating cold facts. All this is taking place at the ‘Spiderhead Penitentiary and Research Institute’ and the man in charge is Steve Abnesti (Chris Hemsworth).

The next morning, Jeff (Miles Teller) who is one of the inmates, is called out for a field visit. He is taken to an unknown location with blindfolds on and then administered the drug titled N-40. When he takes his blindfold off, all he can think about is how beautiful the sight before him is.

In reality, he was taken to a refinery with a lot of waste in front of him. To help him with his words, he’s given another drug called Verbaluce. When he gets back to the institute, he meets Lizzie (Jurnee Smollett) in the kitchen and tells her about the experience.

That night he flashes back to the reason he’s in this place. He was drinking at a party and went out for a drive with his friend before losing control and crashing into a tree, killing his friend in the process.

Jeff is called into the observation room along with Heather (Tess Haubrich), they both show no particular attraction to each other, but once they’re dosed with N-40, they begin expressing their love for each and have sex while Steve and his assistant Mark (Mark Paguio) looked on and recorded the interaction.

Steve explains that the goal of N-40 is to not only induce love within a person momentarily but to see if it can have lasting effects on a person even after the dosage is removed. Meanwhile, Jeff and Lizzie spend more time together and get closer to each other.

Jeff is subjected to the same love experiment with Sarah, this time on a double dose. Jeff is then called in to observe as Sarah and Heather are sat face to face where he has to make a decision.

He has to choose one of them to dose with Darkenfloxx, a drug that agitates a person severely. Jeff doesn’t want either of them to get dosed because he knows what it feels like. Steve tells Jeff that he has to pick one because it will help him with their research into N-40 or Luvactin.

Steve attempts the same exercise with Sarah and Heather but to no avail. Mark begins to worry about the ethical implications of these experiments. It is also revealed that Steve takes doses himself to get an idea of how the others feel.

Steve is backed into a corner and tells Jeff that his higher-ups insist that they carry out this trial, so he brings in Heather and gives her a dose of Darkenfloxx to record Jeff’s reaction.

Something goes wrong as Heather jostles around and she gets an overdose, causing her to lash out. She breaks the furniture in the room and kills herself. Mark and Steve rush to her and Steve drops his keys in a hurry.

Jeff uses this moment to read Steve’s journal and that’s when he finds out Steve actually owns the pharmaceutical company and is responsible for all these trials. He also finds a Bingo card used to name the different drugs.

Two numbers don’t have a gold star on them, N-40 and B-6. By the time Steve comes back into the control room, Jeff has put everything back in its place.

Steve tries to cover up Heather’s death and assures Mark that what they’re doing is for the benefit of society. These emotion-altering drugs are the future.

If you still have doubts about the ending, here’s a full breakdown.

Spiderhead ending explained in detail:

Jeff and Steve

Steve has a talk with Jeff about what happened. He confirms that Heather died, but that her sacrifice will not be in vain. He repeats his belief that these drugs will be the key to avoiding future accidents.

He asks him if he wants something to help him with what he’s going through. The two of them end up on a dose of Laffodil, the drug that makes you laugh no matter what the situation.

Steve tells him that it’s impossible to have a bad time on this, and then tells the story of how his father told him he was going to summer camp and then dropped him off at a foster home and abandoned him.

Sharing his secret

Steve tries out a new drug he names ‘Phobica’ on Lizzie. It makes her terrified of anything that is in front of her, which in this case was a stapler.

She sits with Jeff and tells him how bad it felt. They have one of their bonding moments and Jeff decides to tell her something he’s wanted to from the start. When he was driving the car from the party, not only was his friend there, but also his girlfriend. He was charged with 2 counts of voluntary manslaughter.

She tells him not to be too hard on himself and they head to the kitchen to eat their feelings. Steve shows up and realizes that this could be his chance to carry out the test.

The next day he calls Jeff to the control room and reveals that Lizzie will be injected with Darkenfloxx. Jeff does not agree to it and Steve is left frustrated.

When Mark goes to replenish Jeff’s doses, Jeff asks him for the truth and convinces him to go against Steve and share what’s happening there with the world.

Just following orders

Steve tries the experiment one more time but to convince Jeff, he makes Lizzie confess why she’s actually in there. She had forgotten her baby inside a car during the summer for three hours and was charged with reckless endangerment and involuntary manslaughter.

This doesn’t change how Jeff feels about her and that’s when he uses the control to dose Steve. With Mark’s help, he loaded up Steve with Darkenfloxx and the other terrifying drugs. He wanted to know what B-6 was and uses it on Steve to find out.

Steve tells him that B-6 was a drug to control someone’s actions and he was going to call it Obediex. But because it wasn’t working when he asked Jeff to dose Lizzie, it wasn’t ready yet.

The two of them get into a fight and when Steve gains back control, he doses Lizzie. His dosage is messed up in the process and he can barely keep it together. At that point, Mark is seen arriving with the authorities so Steve has to make a break for it.

Jeff gets rid of Lizzie’s doses and they try to escape the facility but Jeff makes an announcement on the intercom ordering the other inmates to stop them, and they follow it because of the B-6.

Steve gets into his plane and flies away with the remaining drugs while Jeff and Lizzie get into his boat and escape. Steve’s mixture of doses causes him to hallucinate and he crashes into a mountainside while Jeff and Lizzie laugh in joy and enjoy the sunshine once again.


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