In a secret warehouse, Damian comes to see a gang boss for his share of illegal merch to sell. The
boss thinks Damian's acting too twitchy and takes him aside to explain that he's heard
there's a snitch in the gang, and when Damian plays the innocent, the boss confesses he knows
Damian is an undercover cop. Finding himself caught, Damian takes out his gun and begins
defending himself against the incoming thugs using both bullets and martial arts. After
beating up a group that attacks him together, Damian steps back and doesn't see a car coming,
so he's hit rather badly. Fortunately he's sore but still conscious and he goes after the boss to
arrest him only to hear that when the gang learned about Damian's true identity, they also learned
about the existence of his wife. Terrified of the implication, Damian rushes back to his house,
but it's already too late: his wife is dead. Years later, Szymon is starting another class
at the local school when he notices a student is missing for the second time in a row. The
other teens explain this boy has fallen victim to addiction and Emilia, who used to be addicted too,
tried to make him see reason but she was ignored. At that moment, Szymon's son Kamil gets a call
from the missing boy's mother, sadly informing him that the student has been found dead. This
isn't the first time this has happened in this school, the institution has a serious problem with
illegal merch being sold on its premises. Tired of losing students to addiction, Szymon calls his
best friend Damian to get his help, but Damian lets the voicemail pick up the message because
he isn't doing so well himself. Since he lost his wife, he started to depend on alcohol too much and
he got fired from the police force, nowadays he's nothing but a drunkard. However when night falls,
Damian decides to get himself together and pay Szymon a visit to hear him out. Szymon tells him
all about the problems the school is going through while Kamil overhears from the hallway, but Damian
refuses to help, explaining he can't even help himself. Afterward, Damian goes to a store to buy
more alcohol, where three thugs try to steal his waller. Damian first asks for it calmly,
but since they don't take him seriously, he immediately beats them up by grabbing things from
around the store. Another shopper is annoyed by the commotion and gives Damian a bottle of whisky
just to get him to leave quickly. Meanwhile Szymon visits a warehouse at an address he heard one of
the kids mentioning, but as soon as he reaches the door, he's caught red-handed. The next morning,
Damian wakes up to see devastating news on the tv: Szymon was found dead in the warehouse. Because
of the position he was found in, the police are saying he was the one behind the operation and
that he finished things himself because he felt guilty over the loss of his student. Damian can
tell his friend is being framed, so he goes to Szymon's house to investigate, ignoring all the
reporters on the street. He gets to enter because he still has a few buddies in the force, and gets
to comfort Szymon's wife, assuring her that she's right to think her husband was framed. When a
detective makes fun of Kamil for having a criminal dad, Kamil tries to attack him, thus Damian has to
cut in and explain he's just a teenager in shock to save him from getting arrested. Sometime later,
Damian decides he must clean his best friend's name and gets in contact with a shady friend to
acquire fake papers. Then he goes to the school and pretends to be a teacher that has come for an
interview to take Szymon's position, which begins rather awkwardly when the secretary warns him not
to apply because the school's too dangerous. Their conversation is interrupted by Principal Leszek,
who hires Damian because he's the only applicant, and promises he'll be safe because he's hired a
security team. He also calls for his deputy Agata, who will be in charge to show Damian around the
place when he starts to work tomorrow. The next day, Damian arrives at the school and sees Jaro
take some flowers from the memorial for the dead student, so he tries to make him put them back.
Jaro doesn't take this well and calls for his gang buddy Mammoth to beat Damian up, but Mammoth is
still a shy boy under social pressure and barely moves at all. Before things get to escalate,
security leader Chmielski shows up with his men and sends the teens to the principal's
office. He wants to confront Damian as well, but Agata soon comes to his rescue and explains he's
the new teacher. Afterward, Agata shows him around and introduces him to their coworkers,
including chemistry teacher Stefan, before taking him to meet his class, although Kamil isn't coming
back to school yet because he'll need some time to grieve. The class is rather rowdy,
but Damian immediately puts them in their place by taking a student's phone and not falling for
their taunts. One teen isn't as obedient though: Frogface keeps bothering a classmate and ignoring
Damian's warnings until Damian has no choice but to kick him out. Frogface refuses to go, so Agata
sends Chmielski to escort him away. On his way out, Frogface threatens to meet Agata later.
At the end of the day, Agata's at the parking lot when she's suddenly approached by Frogface and his
gang buddies, who have stolen her car keys and now catch her with the intention of getting revenge.
Nearby, Damian discovers someone has slashed his tires, and another teacher offers to take
him home. As soon as they enter the parking lot, they see Agata in danger, and Damian comes to her
rescue, easily beating all the thugs up even if one of them has a weapon. Damian does end
up with a wound on his hand, but it's nowhere near enough to stop him, and Frogface runs away
in fear. Agata takes Damian back into the school to bandage his hand and ask about his past, so
to avoid answering questions, Damian teaches her how to defend herself when a criminal grabs her.
Meanwhile the thugs take Frogface to see Jaro, who is one of the many people that sell illegal merch
at school under the orders of a mysterious man in a bike. When the guy comes closer and takes
off his helmet, he reveals to be Chmielski, whose security company is an excuse to have his men on
campus. Both Jaro and Chmielski are angry because Frogface owes them money and got into trouble for
wanting to get back at Agata, meaning a beating is in order. Jaro asks Mammoth to do it so he can
finally get over his shyness and truly be part of the gang, which he's only joining because he wants
to belong somewhere. The next morning, Damian arrives at school to see his car being towed.
In the teacher's room, everyone is looking at the security cameras, celebrating Damian's victory,
and Leszer explains he is paying for the towing and new tires as thanks. Chmielski's suspicious
of Damian being such a great fighter, but Damian sticks to his story of just being a teacher.
Afterward, Damian goes to the classroom only to discover the security footage has leaked and now
all the students are watching it too. They're super excited to have him as a teacher and keep
showering him with questions, including asking for tips to defend themselves. Damian finds the
idea amusing and takes the class to the gym, offering a deal: if they can beat him, there
won't be a final exam. Obviously they don't get to land even one hit, but at least they have fun,
and during the encounter, Damian notices Kamil comes to watch only to leave when he realizes
who the teacher is. Damian follows Kamil to the changing room to explain he's here to find clues
and prove Szymon's innocent, but Kamil reacts by jumping on him, furious because Damian didn't help
his father when he needed him the most. To Kamil's surprise, Damian agrees and explains he feels
responsible for Szymon's death. It may be too late to save him, but he wants to save the students,
and this makes Kamil accept to keep the secret. At the end of the day, Damian's car is back in
perfect condition, and he asks Agata to go out for a drink. They have lots of fun together at a bar,
but things get tense when Damian notices some men throwing slurs at two girls in love. Damian
comes in their defense, and when the men don't back off, another fight starts. Since these
guys are so drunk, Damian plays around with them instead of beating them quickly, putting a smile
on Agata's face. Afterward, Agata invites Damian to her place, where they arrive already sharing
kisses. When Agata goes to the kitchen to get some wine, Damian's suddenly smacked by a wave
of memories of his wife, showing the sweet moments and the disturbing end. Damian decides he can't do
this now and gets out without saying a word, leaving Agata to reach the worst conclusions.
On his way home, Damian sees Mammoth selling the merch and takes the chance to scold him for it,
reminding him he has a brain and doesn't belong in a gang. Damian also tries to get some intel,
but Mammoth explains he can't say anything before running away. Sometime later at school,
Emilia sees one of her friends buying merch too and tries to warn her against it because she knows
how bad it can be. Jaro immediately interrupts the conversation and sends his guys to grab Emilia,
prompting Kamil to come to save her. Unfortunately he doesn't know how to fight and the gang members
quickly beat him up, then Jaro uses him as an example of what will happen to anyone that
dares to intervene in the future. When Damian arrives at the school, Agata treats him with
cold professionalism instead of the camaraderie from last night. Once class starts, Damian finds
Kamil's face all black-and-blue, but the teen only says he fell, and nobody dares to snitch on Jaro.
Damian scolds them for not defending themselves, but the students remind him they don't know how.
Determined to help them, Damian invites the group to come to his old dojo after class. The place
is in serious need of renovations and that almost makes the students want to quit, but Kamil offers
his support and that inspires everyone to stay. With everyone's help, the dojo gets cleaned in
just a couple of days, and Damian puts extra effort into teaching everyone his best moves,
being delighted to see how quickly they learn. At school, he continues to teach History and tries
to connect with Agata, but she still treats him like a coworker and refuses to hang out. In his
free time, Damian follows some of the gang members to see where they leave their merch and gets the
chance to call the police on them, now all that merch is confiscated by the law. Damian feels
rather pleased with himself for this achievement, but he's not aware of Chmielski keeping an eye
on him as well. During the next gang party, Jaro and the others agree they must do something about
Damian. Sometime later, after the latest training session is over, Damian stays in the dojo to train
by himself when he's suddenly approached by a bunch of men wearing ski masks. They're armed
with sticks and better fighters than the average street thug, but Damian still manages to beat them
all with his mighty skills, although he's sore and bleeding by the end. The next morning at
the school, Damian notices Chmielski's security team displaying some serious wounds and finally
understands they're part of the gang, but for now Damian only teases Chmielski without showing off
his hand. Chmielski is furious that they're being played with this easily, but Jaro promises he
has an idea to take care of it. After class, Jaro and the gang pay a visit to Emilia's dad with the
excuse they want to fix an old watch, which they took from Szymon's the night he was killed. The
poor man doesn't want any trouble and asks them to leave, but when Jaro is about to get violent,
Emilia shows up. After sending her father to the other room, she confronts Jaro, who grabs
her by the hair and demands she collaborate if she doesn't want to lose her dad. The next day,
Damian arrives at the school to find everyone in a very dark mood. Emilia has accused him of taking
advantage of her in the dojo, and now Leszer is firing him. Agata and the students don't trust him
anymore, and as the security team escorts Damian out of the building, Kamil comes after him to
insult him for having tricked him into believing he was a good guy. Damian doesn't reply because he
knows his word won't be believed. Meanwhile Emilia's so overwhelmed with guilt that she
falls back into her old addiction. In the evening, Damian pays her a visit to try to understand what
happened, and Emilia explains the threat against her dad. Damian feels guilty about this too and
takes the merch away from her, but before he can do more, Emilia's dad shows up and kicks Damian
out. Afterward, Damian visits Frogface at the hospital to try to get him to talk, convincing him
to collaborate by showing him his own reflection, which means he's already been abandoned by his
gang. In the end, Frogface confesses they don't bring the merch into the school from outside, they
make it inside the school's labs. Damian rushes to see Agata, intending to share this huge clue,
but Agata still doesn't want anything to do with him and kicks him out. While she turns around to
call the police, Damian steals her school keys since she has access to the whole building. At
the school, Damian finds the security guards are still around and has to sneak around carefully,
hiding in a closet when necessary to avoid being seen. Once the guards are out of the way,
he sneaks into the chemistry lab, where he finds proof that the merch is being made there. Suddenly
Damian hears some steps and hides just in time to see Stefan coming in, because it turns out he's
the one in charge of cooking. Fortunately Stefan leaves quickly to help the security men load the
van, and Damian gets to take a few pictures of what's going on before he gets into his car and
follows the van. By the time Damian makes it to the warehouse, the van has already been emptied
and he gets attacked by the security team, but he easily beats them up by stealing their own taser
and using it against them. Afterward, he calls Agata and leaves her a message in her voicemail
explaining everything. The next day, Damian presents the pictures to Agata and Leszer,
who points out that the pictures are blurry and not good evidence. This is the reason why Damian
didn't go to the police. When Leszer calls Stefan and Chmielski to check, Stefan just says he worked
late on an experiment for class and the security team helped him clean up. Chmielski insists Szymon
was the real dealer and Damian falls for the bait, but the guards stop him before he can get violent.
Damian is kicked out, but Agata stays suspicious, so she goes to see Emilia, whose guilt makes her
confess everything. Later, Damian gets access to the school security cameras and discovers they
deleted all the footage of the merch being moved. Feeling like he's losing control of the case,
Damian begins drinking, and only stops when Agata comes by to apologize for not believing him.
Damian finally shares his whole story with her and Agata kisses him to comfort him before agreeing to
help. Then the duo visits Stefan to demand some answers, but Stefan doesn't give them any names,
he only explains he's cooking for a gang because they threatened with killing his wife. Suddenly,
Chmielski shows up on his bike and shoots Stefan, but he only gives Damian a dirty
look before driving away. The next day at school, Leszek asks Agata to clean Stefan's locker while
he has a meeting with Emilia, who has come to confess. In Stefan's locker, Agata's shocked
to find a hidden notebook with notes about the merch and keeps it for herself. A few hours later,
Kamil and the other students go to the dojo to apologize to Damian because Emilia told them the
truth. The happy reunion's suddenly interrupted by a call from Agata, informing them that Emilia was
attacked and now she's in a coma. When the group makes it to the hospital, Agata shows Damian the
notebook, which includes a map of the warehouse and where to find the hidden merch. Later in the
evening, Damian makes his way to the warehouse, unaware that Chmielski is still keeping an eye
on him. When he arrives, Damian immediately knocks out the first guard he sees then turns around to
be startled by Agata, who has come to help. With the map from the notebook, they easily find the
merch, but soon they find themselves surrounded by Chmielski, Jaro, the gang, and one huge surprise:
the actual leader behind the operation is Leszek, who has given up on the current generation because
they don't care about their studies. Leszek taunts Damian by showing him Szymon's watch,
but the conversation is interrupted by Mammoth, who has seen the error of his way and brought the
whole class with him. A fight between both teams begins then, and Damian watches with pride how
his students beat up the gang, including Jaro. Chmielski is running away so Damian goes after
him, starting a fight with both of them armed. Damian's winning so Chmielski decides to rip some
wires from the wall to try to electrocute him, but Damian disarms him with a kick. When Kamil shows
up and distracts Chmielski, Damian pushes him against the wires and electrocutes him to death.
Afterward, they go looking for Agata, who has been captured by Leszek. The principal has a gun out,
but Damian doesn't care and hits him anyway, instantly releasing Agata. As soon as they
turn around, Leszek shows he's still conscious and takes out another gun from his sock, but
before he can shoot, Kamil releases a container of toys on top of him, now getting him for good.
Damian uses the chance to recover Szymon's watch and hands it to Kamil as a memory of his father
while they watch the police and the ambulances arrive to take care of all the young heroes.