Carl first appears when he meets Bianca Butcher at her house after being telephoned to meet her; albeit it turned out to be a misinterpretation as she originally thought that Carl's number had belonged to her father David Wicks. Bianca soon learns that Carl was a friend of Derek Branning, whom he later finds out to have died almost a year ago, and that he soon claims to know his daughter Alice Branning. He visits Alice, who gives him the box that contained the phone number, which Alice says was found by Ian Beale. However. Bianca's friend Kat Moon is already aware of Carl's deception and warns Bianca and Alice about him. Carl later visits Ian, who denies knowing Derek, and slowly deduces that he previously took £10,000 from the box that Derek owed him. The next day, Carl sees his ex-girlfriend, Kirsty Branning, who says she is now married and pregnant, and he has no reason to stay. At the restaurant, Carl makes Ian confess to taking his money, and tells Ian to pay him £500 a week for a possible future between them. He then tells Kirsty he is not leaving. Ian soon realises the situation between Carl and Kirsty, so he threatens to tell Kirsty about Carl's blackmail. In response, Carl burns Ian's hand before warning him not to mess with him again.
Derek's brither Joey Branning catches Carl dealing drugs in the nightclub, R&R and informs his brother Max Branning, who confronts Carl in addition to knowing about his issue with Kirsty; Max's wife. A prompting conflict between them provokes Max into calling the police under the brief that Carl had Kirsty virtually mugged by his brother Adam White. When being questioned, Carl falsely appears to have no drugs when being checked in front of Kirsty. Upon managing get one over his rival, Carl makes it clear to Max that he intends to ruin his marriage to Kathy. To further sabotage Max and his business, Carl deliberately cuts the brakes on his car, then takes Max's associate Phil Mitchell as his passenger before taking off his seat as he intentionally runs into a wall - critically injuring Phil. While Phil is hospitalised, Carl takes the opportunity to frame Max for cutting the brakes and also forces Ian to become a false witness under the pretence of cancelling the debt. Max is arrested and released on bail, until Carl goads him into attacking him, and he is remanded in custody. Max ends his relationship with Kirsty under Carl's instructions, as Carl resorts to threaten Max's daughter Lauren Branning.
Carl attempts to take over Phil's businesses while he is in hospital, and after Shirley Carter challenges him, she mysteriously disappears. Carl attempts to reconcile with Kirsty but she rejects him. However, she later approaches him and they have sex, but he sees her stealing £1000 from him the next morning. On the day of Max's trial, Ian fails to turn up, and Max is released without charge, to Carl's fury. Max and Phil then kidnap Carl and Phil offers Max the chance to kill him. Max declines and leaves, so Phil prepares to kill him instead until Carl implies that he caused harm to Shirley and knows where she is. He leads Phil to a block of run-down flats where Shirley is staying with her sister, Tina Carter. It is revealed that Carl threatened Shirley to stay away from Walford or he would harm Phil's family. Carl leaves, but Phil confronts him later. Carl declares that he has contacts inside prison who can harm his son if Phil does anything to him. Carl then tells Max that he had sex with Kirsty while he was in prison, leading to Max ending his relationship with Kirsty.
When Roxy Mitchell splits from her husband Alfie Moon immediately after their wedding, Carl flirts with a drunken Roxy. She insists she is not interested, but later waits outside his new flat and they have sex when he returns. They start a relationship, which Roxy's sister Ronnie Mitchell disapproves of and tries to split them up. She confronts Carl, who is violent towards her and a final threat leads to her hitting him over the head with a champagne bottle; he falls unconscious. She ties him up in Phil's garage and the next day tells him to leave Walford and never return, but he ignores her and attempts to rape her, kissing her forcefully. She slams the boot of a car onto his head, killing him, and has the car crushed with his body inside.