"As One Door Closes..." is the 599th episode of Casualty and the 9th episode of the 22nd series.
Synopsis[]
Josh finds out that Laura Merriman is too mentally unwell to appear in court after stabbing him last season. Harry installs a new Blood gas machine but requires a huge form being filled out each time and each form earns the department money. After being continuously bullied and threatened with a knife on an estate by a group of youths, Matty takes matters into his own hands and strikes back with a knife causing serious harm to the adolescent. Josh has severe flashbacks between this stabbing and his own which makes it difficult for him to work or concentrate. Josh suffers a major panic attack in the ambulance forcing Dixie to call for another unit to take the patient. Toby makes yet another mistake after not log rolling the patient to find the other knife wound, also he has too much faith in the machine and gives the patient too much saline for his hemoglobin levels. Harry orders that no one uses the blood gas machine as it transpires it is giving false readings. Matty tries to run away with his parents to Poland after footage of him initiating the stabbing is found on his phone. As they are driving away they stop after Matty starts to hemorrhage. Adam has been making a blog online and is giving overviews of all the staff names along with nicknames. Marilyn decides that they only need 1 band 8 nurse so either Charlie or Tess needs to go and be replaced with a band 5 nurse to save £1,500. For revenge on Adam's prank Kelsey goes to let down his tyres, she assumes he has the fanciest car, it turns out that instead of his she has flattened Marilyn's.