He was known to be the best friend of Grünvald Karlsson and Grünvald borrowed out his Karate Kid movie to him. Without Grünvald knowning, Stefan copied the movie and sold it to many other class mate, resulting in them injuring themselfs trying to learn the moves from the movies. Grünvald tried to reason with him but Stefan just laughed at him, leaving Grünvald the angry and grumpy man he is today.
Many years later Stefan was now a crimelord in selling illegal pirate copies all over Sweden and even was undercover as a Swedish Anti-Piracy Bureau agent. He was first seen when his minion nicknamed the 'Rat' has failed, resulting him in whacking his hand with a ruler.
He was later shown at the interrogation of the Rat at the police station only mentioning himself as Holk for Späck and Grünvald without him recognizing Holk. They had a talk with Margareta Ohren about the investigation about the pirate copy case and he made sure that Grünvald and Späck stayed out of his way, resulting in Grünvald leaving the room in anger.
Back as The Boss, he ordered his minion who is nicknamed the Unicorn to execute The Rat, he also as Holk told Späck to let The Rat go free.
He is seen again when he and Margareta Ohren sees Iren Snusk's image of The Unicorn's identikit. He went to The Unicorn's apartment to tell him to leave the country, but fails when The Unicorn tells him about things he needs to do with his kids. He then ordered The Unicorn to go to the witness apartment to scare her so much that she will tell the cops that she saw nothing.
He is seen again last time as the Boss when he was ready to depart with his league when Grünvald came for a visit, discarding his Boss mask and answered the door. Just as Grünvald was about to apologize about his anger issues eariler, he notices a fake sequel to The Seventh Seal. Grünvald then realized that Holk is the one behind all pirate copying and remembered that he was his old classmate and former best friend when Hold revealed same head band. He then forces Grünvald to watch his version of The Karate Kid on a TV while explaining that he always wanted to eliminate him and that his ship will depart at midnight.
As Späck and Irene Snusk arrived, Holk was about to execute Grünvald when the two burst in to free their colleague. Holk then escaped with the cops in pursuit. When he arrived he ordered his men to fire at the cops while Grünvald followed him, shooting him at his ankle.
At the same time it was revealed that Ohren worked for him the whole time.
Despite being injured, Grünvald managed to get to him to settle things up with a karate fight. Holk dominates Grünvald with his poorily skills and when he was about to do his move of the crane, Grünvald grabs his foot and shoves him off, scoffing that if he had the original movie instead of the copy, he would know the proper move of the crane, kicking Holk down.
As Holk was about to be taken away, he snatches a cop's gun and tries to kill Grünvald once more when Späck got in the way, shooting him instead. At this moment, Holk was gunned down by Irene and Grünvald. It was then revealed that Späck survived the shot and that the bullet only hit the steak he hid in his jacket. During the song 'Sudda sudda bort din sura min', Holk somehow gets back to life and joins the dance.