Callum "Halfway" Highway is a fictional character from the BBC soap opera EastEnders, played by Tony Clay. He was introduced in the episode first broadcast in the United Kingdom on 1 January 2018. Callum is introduced as a friend of the Carter family, which was not publicised beforehand. Callum is a comedic character who is jovial, dopey and "happy-go-lucky" who wears shabby clothing and beanie hats. Callum's initial stint on the show focuses on his relationship with the Carter family and establishing a relationship with Whitney Dean.

Whitney Dean is a fictional character from the BBC soap opera EastEnders, played by Shona McGarty. The character is the ward of long-running character Bianca Jackson and was introduced on 1 April 2008 when Palmer returned to the series after a nine-year absence. Whitney is described by executive producer Diederick Santer as both an equal to, and younger version of Bianca, and is the oldest of Bianca's four children. Whitney was absent from the soap across four weeks in 2012 when McGarty was suspended for repeated lateness. McGarty took a short break in 2017 and Whitney departed on 29 May and returned on 31 July of that year. On 1 June 2018, McGarty filmed her 1,000th episode as Whitney. On 29 July 2023, it was announced that McGarty had resigned from her role after fifteen years, and Whitney would be leaving the soap in May 2024.