Stuart arrives in a blacked-out car, watching Mick Carter, though the car's arrival worries several other people. While Mick is alone in The Queen Victoria pub, a masked man grabs him. However, this is proven to be a prank by Stuart, who says he has been watching Mick all day. They head to the bar of the pub, where Mick's wife, Linda Carter, is not happy to see Stuart. Stuart's brother, Callum "Halfway" Highway, talks about how he was injured in Iraq by shrapnel, but Stuart later tells Halfway he knows he is lying and to tell him what really happened. Stuart showed his darker side as he tricked Mick into thinking he slept with Hayley. Stuart also had a violent outburst when someone hid his phone for a prank. Mick saw photos on Stuart's phone which made him think Stuart was a paedophile. Stuart later said he was actually hunting them down. That moment, he met up with Gavin Thompson who was there to meet a 14 year old girl. Stuart said there is no 14 year old, and that Gavin has actually been talking to Stuart, who makes a citizens arrest. Stuard ends his stint as a paedophile hunter after beating up a man named Fred Lewis who he mistakenly identified as a paedophile. Stuart later reveals to Callum his obsession with paedophile hunting was because he was sexually abused as a child.
When Tina returns from her holiday to Spain, she meets Stuart. They had previously been friends in her childhood. They decide to celebrate their reconnection by attending an 80s night at the E20 nightclub. Stuart requests a song named "We Call It Accieed" which gives Tina a flashback to her childhood where a boy in her and Mick's friend group tortured her in a car. This makes her believe Stuart did it to her. Tina tells Mick and Linda, who cut Stuart from their lives. As revenge, Stuart keys his car and tells everyone in the Square that Tina did it. Tina confronts Stuart in The Archers garage about this. They have an argument, which leads to Tina hitting him over the head with a wrench. Stuart tells the police this, leading to Tina being arrested but later being released.
Stuart terrorises Mick and Linda after this event, culminating in his shooting in the Queen Victoria. It is revealed that he shot himself, however he frames Mick for his shooting, sending Mick to prison. Stuart has a friend inside who essentially presides over every prisoner, and asks him to tell everyone in the prison that Mick is a paedophile, therefore making Mick's time in prison incredibly tricky.
Mick is released from prison and tries to scare Stuart out of Walford, however he returns soon enough to live with Dot Branning.
Dr. Legg goes to live with Dot in Albert Square in October 2018, and revealed that he has pancreatic cancer. While Dr Legg is visiting Dot, Stuart is also residing there and helps around the house and talks to Dot. Dr Legg appears to be sceptical of Stuart's intentions. After Dot has gone to bed, Dr Legg tells Stuart he got him wrong and thinks he is a good person. Stuart thanks him, and pulls out a wallet from his back pocket. He tells Dr Legg that it is his wallet and that he left it in the kitchen. Dr Legg looks inside and notices his photo of his wife is gone, as Stuart walks out and says "night-night" with a grin.