Billy Mitchell (EastEnders) revealed in 2006 that the role was extended by "coincidence and chance": "I was offered four episodes and here I am, about 800 later. [...] Ross Kemp (Grant) said that he was leaving, and there was a gap in the Mitchell family, so they brought me back to do stuff towards his leaving. After that they offered me a year." Billy was reintroduced in 1999, making recurring appearances. He was involved in the leaving storyline of Grant Mitchell in October 1999, before returning later in the year as a regular character. When Billy was first introduced, he was depicted as
Ross Kemp in Afghanistan during its tour, 5 hostile and 4 accident. Kemp was travelling in a convoy in which a corporal was killed by a mine strike on his vehicle. He also witnessed the death of a private. The film was dedicated to the dead soldiers, and the men and families of the Vikings. Following the first series, Kemp's next project was to be a documentary on drugs in Thailand for Sky. Kemp stated he would love to return to Helmand in six months or a year to document any progress made in the region by the International Security Assistance Force (ISAF) mission.