[71] The episodes introduce John Gaskell, portrayed by Paul McGann, and heavily focus on Jac Naylor (Marcel), Ric Griffin (Quarshie) and Henrik Hanssen (Henry).
Gaskell arrives and tries to help the hospital through their challenges but creates conflict with Jac, who is battling personal and professional issues at the same time.
On the episode, Harper commented, "You'll see our NHS heroes instinctively rush towards the hospital's greatest peril yet in a story that changes lives forever".
[74] At the 2018 Writers' Guild of Great Britain Awards, Peter Mattessi won the Best Long Running TV Series category for his episode "Rocket Man".
[75] Holby City was shortlisted in the "Best Soap/Continuing Drama" category at the 2018 Broadcast Awards, but lost out to Channel 4 soap opera Hollyoaks.
[76] Judges for the awards praised Jasmine's death and felt that it was "a reminder that Holby's heroes don't always save the day.
Guy Henry portrays Henrik Hanssen, the hospital's chief executive officer and a consultant general surgeon.
Hugh Quarshie plays Ric Griffin, the clinical lead of Keller ward, and later the Acute Assessment Unit, and a consultant general surgeon, who later acted as the hospital's CEO.
James Anderson acts as Oliver Valentine, a specialist registrar in cardiothoracics on Darwin, and later in general surgery on the AAU.
Joe McFadden plays Raf di Lucca, a general surgical specialist registrar on the AAU and later, Keller ward.
[2] Ben Hull, Jules Robertson and Marc Elliott continue their semi-regular roles as consultant obstetrician/gynaecologist Derwood "Mr T" Thompson, clinical audit assistant (and later, porter) Jason Haynes and general surgical specialist registrar Isaac Mayfield.
[84] Akudolu told Laura-Jayne Tyler of Inside Soap that Hull had also left his role as Mr. Thompson and the characters would depart together in episode 36.
[85] She also revealed that both characters could return in the future, saying "our producer has said to me that it's a revolving door, so it would be lovely to pop back for a bunch of episodes.
[92] On 10 February 2017, it was announced that former Casualty character Ben "Lofty" Chiltern, portrayed by Lee Mead, would join the cast of Holby City.
[39] The reintroduction of Fran Reynolds (Carli Norris), an agency nurse who shared a backstory with Jac, was revealed on 7 March 2017.
[64] Christian Vit joined the cast as Matteo Rossini, a consultant on cardiothoracic surgery ward, Darwin, and makes his first appearance in episode 8.
[97] On 10 February 2017, it was announced that Ayesha Dharker and David Ajao would join the cast as general surgeon Nina Karnik, who is married to Matteo, and F1 Damon Ford respectively.
[99] Paul McGann was announced to be joining the cast in April 2017 as surgeon Professor John Gaskell, with his first scenes airing in December.
The character is billed as a "surgical star with irrepressible charm", while McGann was delighted to join the show and called John "interesting".
[101] The introductions of F1 doctors Nicky McKendrick, portrayed by Belinda Owusu, and Meena Chowdhury, played by Salma Hoque, were announced on 29 September 2017.
[54] Tessa Peake-Jones reprises her role as Imelda Cousins, the former acting CEO of the hospital who last appeared in the fifteenth series, in episode 3.
[25] The reintroduction of Kyle Greenham (Alan Morrissey), an agency nurse and Dom's former partner, was revealed on 7 March 2017;[105] he guest appears in episode 27.