This story is written by Stephen Churchett whom appeared as DI Larkin in s5e4 (Foreign Bodies).
The only TV appearance by Karen E. Jones. She passed away 2 days before this was screened.
The final TV appearance by Una Brandon-Jones.
The second a final appearance by Penelope Freeman as consultant.
The first of 4 appearances by Lorraine Bruce. She plays 2 characters in total. Her role is as a nurse here.