The fourth series of Our Girl is shaping up to be a big one - with Michelle Keegan telling RadioTimes.com that viewers can expect a "more emotionally led" storyline in what will be her last series in the lead role.
As usual Keegan will be joined by a large supporting cast, although for the first time since Our Girl began there's no Ben Aldridge (Captain James) - with the actor having left the show at the end of series three to pursue other projects.
There are a host of new faces joining, however, as well as a bunch of returning favourites - here's the lowdown on the main cast members...
Michelle Keegan plays Georgie Lane
Who is Georgie Lane? Georgie is an army medic and absolutely loves the military. The main character since series two, Georgie has completed tours in Afghanistan, Nepal, Nigeria and Belize and is known for being gutsy and brave. She lost her ex-fiancé Elvis when he was killed in Afghanistan.
What else has Michelle Keegan been in? Keegan shot to stardom during her time on Coronation Street, where she played Tina McIntyre from 2007 to 2014 picking up a slew of awards in the process.
Since she left the soap, she's appeared in a number of other programmes including three-part ITV drama Tina and Bobby and the hit Sky One comedy Brassic.
Sean Sagar plays Private Monk
Who is Private Monk? Monk is a member of 2 section who joined the cast at the start of season two and has travelled on a number of missions with the team.
What else has Sean Sagar been in? In addition to starring in Our Girl since series two, Sagar appeared in ITV drama Sticks and Stones last year and was part of the cast for BBC Three comedy series Just a Couple.
Film roles have included small parts in Rapman's Blue Story and Guy Ritchie's The Gentlemen.
Sean Ward plays Private Fingers
Who is Private Fingers? Private “Fingers” has been with Our Girl since series one. Along with the rest of 2-Section he's been on several tours with plenty of experience of perilous situations, including Georgie’s dramatic kidnapping in series two.
What else has Sean Ward been in? Like series star Keegan, Ward is a Coronation Street alumni - appearing as Callum Logan on the soap in 2014 and 2015.
Other roles have included the miniseries Island at War and a recurring role on Doctors.
Rolan Bell plays Sergeant King
Who is Sergeant King? Respected by the men within 2 section, King knows how to joke around but can pull rank and demand authority when it’s called for.
What else has Rolan Bell been in? Another former soap star, Bell was part of the cast on EastEnders back in 2009 - playing Theo. He's also made appearances on Doctors and ITV crime drama Scott & Bailey.
Simon Lennon plays Private Brains
Who is Private Brains? Brains has always been seen as the clever one in 2 section - hence his nickname.
What else has Simon Lennon been in? Lennon's TV appearances outside of Our Girl have been relatively sparse - but he did have a role in an episode of Grantchester's third season in 2017.
Mark Armstrong plays Spanner
Who is Spanner? Spanner is a special forces agent who first joined the cast in series 2.
What else has Mark Armstrong been in? Armstrong's role on Our Girl is easily his most prominent TV job to date - although he did appear on an episode of Midsomer Murders back in 2012.
Jack Parry-Jones plays Jackson
Who is Jackson? Another special forces agent, Jackson also joined the cast in series two.
What else has Jack Parry-Jones been in? Parry-Jones has appeared in a range of TV shows, including appearances on The Crown and Holby City, in addition to a regular role on Welsh crime drama Bang.
Ben Batt plays Blue
Who is Blue? Blue is also part of the special forces squadron and was introduced to Our Girl last series.
What else has Ben Batt been in? Batt is best known role is playing Joe Pritchard in Channel 4's Shameless while other TV appearances have included roles on Scott & Bailey, The Village and Sirens.
On the big screen, he's had small roles in Captain America: The First Avenger and The Promise.
Danny-Boy Hatchard plays Private Rhett 'Cheese' Charlton
Who is Private Rhett 'Cheese' Charlton? Cheese is a new character for series four and is described as "confident and cool".
A new member of 2 section, he's said to like a bit of banter but also has a darker, slightly manipulative side to him.
What else has Danny-Boy Hatchard been in? Hatchard is best known for playing Lee Carter on EastEnders - a role that lasted six years (on and off) from 2014 to the beginning of this year.
Other appearances have included Not Going Out and the 2014 film We Still Kill the Old Way.
Kaine Zajaz plays Throbber
Who is Throbber? Throbber is another character new to 2 section for series 4. Speaking to RadioTimes.com, Michelle Keegan described him as "a bit of a naughty character, a bit of a risk taker, bit of a wildcard."
What else has Kaine Zajaz been in? Zajaz has made an array of TV appearances prior to joining the cast of Our Girl - including Raised by Wolves, Hang Ups and Informer.
Amy-Leigh Hickman plays Mimi
Who is Mimi? Mimi is new for series 2 and was described by Keegan as a bit "like a younger Georgie." She's new to the military and gets a lot of guidance from Georgie.
What else has Amy-Leigh Hickman been in? Hickman first appeared on TV screens as part of the cast on CBBC shows Tracy Beaker Returns and The Dumping Ground, while more recently she's starred as Linzi Bragg on EastEnders and Nasreen Paracha in the Channel 4 drama Ackley Bridge.
Nico Mirallegro plays Prof
Who is Prof? Also new for series four, not too much is know about Prof so far, but Keegan teased that he was "quite a complex character and he's got a lot of layers...and you'll see that as the series progresses and you see more about his storyline and his personal journey."
What else has Nico Mirallegro been in? Mirallegro has an extensive list of TV credits to his name including playing Barry "Newt" Newton in Hollyoaks from 2007 to 2010, Finn Nelson in My Mad Fat Diary and Joe Middleton in The Village, the latter of which saw him nominated for a BAFTA.
Josh Bowman plays Dr Antonio
Who is Dr Antonio? Dr Antonio is another character who is joining for the fourth run - although not much is known about his character so far.
What else has Josh Bowman been in? Bowman's most high-profile role to date is in the US drama Revenge, in which he played Daniel Grayson. Other parts have included appearances in Holby City and Doctor Who.
Angela Lonsdale plays Grace Lane
Who is Grace Lane? Grace is Georgie's mother and is known to be quite fun-loving, although she sometimes struggles with the fact that her daughter is always away with the army.
What else is Angela Lonsdale been in? Lonsdale has starred in a variety of British TV staples, including being part of the cast of Coronation Street (where she played Emma Taylor from 2000 to 2003) and smaller roles on Holby City, Doctors and The Bill.
Sean Gilder plays Max Lane
Who is Max Lane? Max is Georgie's father.
What else has Sean Gilder been in? Gilder recently appeared in ITV true crime drama White House Farm and will be part of the cast for the upcoming second season of His Dark Materials.
Other roles in his extensive career have included parts on shows such as Poldark, Shameless and The Last Kingdom.