Little Sister

"Little Sister" is the 1023rd episode of Casualty and the 19th episode of the 31st series. It was preceded by "Back to School". The episode was directed by Fiona Walton and written by Jeff Povey and Joseph Wilde.

Synopsis
Belle, a supervisor from a young offenders institute, is brought into the ED after being struck over the head with a wok by one of her charges, and Iain is dismayed to discover the assailant in question is his estranged younger sister Gem. However, there is more to Belle and Gem's conflict than first meets the eye, as the youth worker demonstrates a damaging attitude toward the young people in her care. Meanwhile, Connie treats Jamieson, who injured himself while exercising, and is claiming to be much younger than he appears. The case takes a more dangerous turn when the truth about his age is revealed, along with the motives of his much-younger fiancée.