[3] While writing for the series, creator Tony Grounds admitted he aimed to shed light on emergency disaster relief, as the army often participate in it.

[4] Before choosing a location for the series's setting, he researched areas that were often struck with natural disasters and helped by the British Army's involvement.

[5] After Luke Pasqualino told Grounds that he would leave after Part 1 of the series, his character's death was written in to explain his absence, a decision he felt was a good one for dramatic effect.

[10] For the Nigerian section, a training mission was set to turn into a rescue one after many schoolgirls go missing due to Boko Haram.

[11] Grounds chose Bangladesh as the final part as he was interested in stories about Rohingya Muslims crossing the border from Myanmar and living in refugee camps, and found drug lords to be an intimidating enemy.

[12] Grounds detailed that he spent a "long time listening to soldiers and people" from around the countries to achieve accuracy and authenticity of the struggles in the areas.

[15] Part 2 was filmed in South Africa and in the Taman Negara jungle in Malaysia over a nine-month period, which Keegan described as "really long".

[12] Aldridge described filming in the Malaysian jungle as being "beautiful but tough", attributing the humidity, insects, and heavy makeup as reasons why.

[2] Captain James and Elvis Harte both returned for the first part of series 3, with Ben Aldridge and Luke Pasqualino, respectively, set to reprise their roles.

[10] Keegan teased the series showcasing Georgie "throwing herself into work" as a method of coping, adding that her character is "definitely not over Elvis at all and you’ll see throughout the episodes that his death has really affected her".

[21] Aldridge also reprised his role, teasing that Captain James was also "trying to lose himself in his work" and "steadily becomes more war weary than ever and starts to question his future with the British Army".

[11] Olly Rix was cast as a new character, 'Bones', whom he described as "a tricky kind of guy" and "abrasive, brash and yet highly competent as a soldier".

[11] Maisie, Rab, Sergeant King, Brains, Monk, and Fingers all returned, with their actors reprising their respective roles.