As a little boy, Nick grew up with an abusive father who was a drug addict. He had a bike and enjoyed riding it for a time since he was without a care. Unfortunately, his father stole and pawned the bike for crack and Nick was devastated to the point where he finally lash out at his father and assaulted him.
Nick spent most of his childhood in the Juvenile Hall for the attack and met Carl and they became friends.
After Carl was released from Juvie, Nick joined him because of his eighteenth birthday. Since he had nowhere to go, Nick came to live at the Gallagher House with Carl and they continued to be friends.
When Carl returned to school, he brings Nick along with him. The two smuggle a backpack filled with a cache of weapons into the school and begin running a business selling them. Teachers quickly catch on including the school principal and a math teacher who approach Carl and Nick to their surprise, ask to purchase guns of their own.
Nick helped Carl in trying to get the affections of Dominique Winslow who continued to rebuff the latter. Nick later purchased a bike and it looked liked the one he had in his childhood and he explains why it meant so much. Nick's action also gave Carl an idea and he bought Dominique a bike as well, somewhat flattering her.
When the Gallaghers were kicked out of their home, Nick tried to help Carl in finding a new spot for them though have no luck. Nick also loses his beloved bike and becomes upset. He ignores Carl's suggestion of moving on and explains he feels disrespected by it, which causes him to buy a gun. However, Nick gets happy when given a car even though he doesn't have his license.
Later on, Nick, Carl and Debbie are in the car driving to Debbie's baby's gender party, they see a kid on his bike. Nick attempts to reclaim his bike and get revenge but Carl tells him that it's not worth it and he seems to agree as they make it to the party, though he slips away. When Carl notices Nick driving off, he realizes where he's going and followed him. He finds Nick covered in blood with his bike, sitting on the other kid's porch with a bloody hammer, pondering on his thoughts as crying and screaming is heard from inside the house. Carl walks up to the porch and questions Nick on what he did, before peeking in the house to see the dead body of the kid with his grieving mother and pukes at the sight. This implied Nick killed the boy with a hammer in revenge and that the boy's mother is holding her dead son.
In a somber tone, Nick tells Carl that he called the cops and suggests that he leave quickly, as Carl asks him why he did it but Nick doesn't answer and only looks at him. This suggested he regretted not listening to Carl earlier about letting go or not simply just taking his bike back and leaving. Sirens are heard, as a reluctant Carl leaves and watches from a distance as his friend surrenders to the cops before being taken away.
Carl later tells Fiona of Nick's actions and how they traumatized him. Carl decided that he no longer wants to be in the drug business or anything thug related.