He was first introduced in a Red Button episode, which explores Sam Nicholls's (Charlotte Salt) fictional backstory as a medic in the army, alongside Iain with whom she is having an affair.

He returned in August 2013 this time as a trainee paramedic, who works alongside Jeff Collier (Matt Bardock) and Dixie Dixon (Jane Hazlegrove).

In November 2013, the character was the focus of another Red Button special, which helped to mark Remembrance Day and explore Iain's time in the army and relationship with Sam.

Following an incident in which Iain is held hostage and Big Mac (Charles Dale) is injured, he leaves Holby in the episode broadcast on 22 March 2014.

Iain establishes a romantic relationship with nurse Rita Freeman (Chloe Howman), which producer Erika Hossington said would be different from the other romances on the show.

Hazlegrove reprised her role as Dixie, who offers Iain a job with the Helicopter Emergency Medical Service (HEMS), and he departed on 21 September 2019.

Upon Iain's return, he immediately sets out to help his boss Jan Jenning (Di Botcher), who is being forced to smuggle drugs into a prison for her son.

Towards the end of 2021, producers cast Stevenson's wife Lauren Crace as Iain's HEMS partner and new love interest, Chrissie Danes.

[1]The character's biography on the official Casualty website noted that Iain's "mental scars" from his time in the army had not fully healed, and his behaviour was often affected by the "bad memories".

[6] The episode is set in Camp Bastion and explores Sam's time working on a Medical Emergency Response helicopter, alongside Iain, with whom she is having an affair.

Titled "Scars and Nightmares", the episode was broadcast to mark Remembrance Day and explored Iain's time in the army and his feelings for Sam.

[12] The show's executive producer Oliver Kent explained that the team wanted to return to Sam and Iain's history, as it had briefly been touched on, but not explored any further until that point.

[24] On the first anniversary of Jeff's death, Iain and Dixie are sent for Height and Rescue Training (HART), and they are both attracted to their instructor Jess Cranham (Kerry Bennett).

[26] Howman told Elaine Reilly of What's on TV that Iain is the first man Rita has dated since her former husband Mark Richie (Joel Beckett), who was a paedophile.

The rest of the ED staff give Iain the "cold shoulder" over his treatment of Rita, which makes him feel bad and he decides to track down Mark.

"[31] The first member to be introduced is Iain's younger sister Gemma "Gem" Dean (Rebecca Ryan), who turns up at the ambulance station unexpectedly.

[33] Elaine Reilly of What's on TV noted that the siblings had "a complicated relationship", explaining that Iain wanted to make up for not getting in contact with his family when he returned home from Afghanistan.

[40] The episode follows the previous series' cliffhanger which saw the ambulance carrying Iain, Ruby Spark (Maddy Hill), and the injured doctor Alicia Munroe (Chelsea Halfpenny) flip on its side, causing a major incident.

It's what comes before the crash that leaves questions opened to be answered..."[41] The episode reveals that Iain swerved to miss Mia Bellis (Simona Zivkovska) when she jumped from a bridge.

[42] Allison Jones of Inside Soap noted that with Iain having to make such a difficult decision in the moment, the aftermath is "devastating" for him and would affect him for weeks to come.

[43] He blames himself and admits to his boss Jan Jenning (Di Botcher) that he could have stopped Mia from jumping off the bridge, but he chose to attend the call out to Alicia instead.

[44] Sarah Ellis of Inside Soap believed the development would come as a big shock to viewers, with many of them finding the episode in which Iain makes his decision sad to watch.

[44] Stevenson pointed out that post-traumatic stress disorder and depression do not always manifest in the same way, so the storyline might not "hit home" with everyone, but he commended the producers for allowing Iain's story to span 47 episodes of Casualty.

[45] As the crossover continues, Connie and her rival Jac Naylor (Rosie Marcel) attempt to save the lives of their colleagues, with Sacha Levy (Bob Barrett) also in trouble.

[47] The show's executive producer Simon Harper praised Stevenson for "carrying the lion's share" of the work in the thirty-third series and said the door would be open for a return.

[50] Stevenson was also grateful that Hazlegrove returned as Dixie and he enjoyed working with her, Botcher and Hill, calling their characters "the three women who have been his anchor points while he's been at Holby".

[55] Towards the end of 2021, producers cast Stevenson's wife and fellow actor Lauren Crace as Chrissie Danes, Iain's HEMS partner and new love interest.

[61] While reviewing the show, Alison Graham of the Radio Times observed that Iain and Gemma's reunion was "a touching story" that had been "bubbling for a wee while".

[66] Holly Wade of the Radio Times listed Iain's memorable moments as his arrival in 2012, his return as a paramedic, and how he "proved his worth" by rescuing a patient from a bus crash.

She also named Iain, Dylan Keogh (Will Beck), and David Hide (Jason Durr) as "three incredibly complex members of the ED who are interesting on screen because of what they've been through.