"Waste of Space" is the 545th episode of Casualty and the third episode of the 21st series. It was preceded by "Different Worlds - Part Two" and followed by "Heads Together". The episode was directed by Shani S. Grewal and written by Robin Mukherjee.
This episode marks the first appearance of paramedic Kathleen "Dixie" Dixon portrayed by Jane Hazlegrove, who left the show in the 2016 episode "The Good Life" after over 9 years on the show. It also features the first appearance of paramedic Cynthia "Cyd" Pyke, portrayed by Joanne King, who remained on the show for just under a year.
Nathan is continuing to worry about his future and becomes distressed when he cuts himself. Selena convinces him to take a blood test and he is glad to have her on his side, but what will his results say? Harry turns detective when a woman is brought in following a suspected overdose. Events lead him to suspect her GP of acting inappropriately. Meanwhile,Ellen is on a mission to convert the others to her health kick. An aggravated Kelsey decides a practical joke is the best way to get back at her, but her actions end up having unexpected consequences for Alice. New paramedics Dixie and Cyd arrive and Josh is unimpressed by their laid-back attitude. When Dixie criticises Josh's management, he decides to break the two of them up.
- Main article: Waste of Space/Gallery.
Images and stills from the episode were first released after the airing of "Different Worlds - Part Two".