The twenty-fifth series of the British medical drama television series Casualty commenced airing in the United Kingdom on BBC One on 4 September 2010 and concluded on 6 August 2011. The series featured several crossovers with spin-off show Holby City. This series has featured the death of Polly Emmerson (Sophia Di Martino), and the departures of Adam Trueman (Tristan Gemmill), Yuki Reid (Will Sharpe), and Kirsty Clements (Lucy Gaskell). This series has welcomed Dylan Keogh (William Beck) and Madiha "Mads" Durrani (Hasina Haque), with the latter departing at the end of the series; and has seen the return of Linda Andrews (Christine Tremarco). Cast Overview Jaye Jacobs will guest-star as her Holby City character Donna Jackson in the opening episode, as part of Kent's plan to have characters from the two shows cross-over several times a year. While Jacobs has appeared in several Casualty@Holby City episodes, she had never before appeared in Casualty itself, and deemed the two shows very different, to the extent that it felt like "doing a completely different job". In terms of her character's development, Jacobs stated that "Donna really has to put herself on the line in this episode and its not something she's used to doing", explaining that now she has her orphaned niece to care for her priorities have changed: "She's had to accept some responsibility and it's not now just about which man she's going to sleep with next". Guy Henry guest-starred as his Holby City character Henrik Hanssen in episode 24. The character had only recently joined the Holby City cast as the hospital's chief executive officer. Hasina Haque joined the Casualty cast as new staff nurse, Madiha "Mads" Durrani in episode 1. Mads' storylines included: an attraction to Lenny Lyons and being raped by her taxi driver. She left in the episode 47, the series' finale. Cheryl Campbell joined the cast for ten episodes as the new joint clinical lead, Miriam Turner, in episode 25. Miriam fought against Nick for the sole clinical lead position, which she won. However, she then decided to return the position to Nick and left the show in episode 35. New trust doctor, Dylan Keogh (William Beck) arrived in episode 28 to replace Ruth following her sectioning in episode 21. Ruth returned to the ED as a doctor in episode 45, but Dylan continued to appear. Former Waterloo Road star, Christine Tremarco who guest-starred in