I haven't seen the earlier series under the same name but understand they're not connected in any case, having completely different characters and story lines. This unlikely tale started off for the first two episodes very like the late unlamented US failed drama "American Odyssey" which the BBC also showed, where another good-looking English actress is kidnapped by jihadists while on a foreign tour of duty, getting miraculously rescued before she comes to any real harm.
It got a bit silly and confused when she returns home finding herself having to choose between her ex-army lover who jilted her on their wedding day and who improbably gets the task of rescuing her from captivity and her new civilian doctor boy-friend. Moreover it looks like the "Jihad John" English terrorist-convert character who threatened her life earlier has returned to England to commit a major attack coincidentally in the same Manchester from where they both hail.
Michelle Keegan is the torn-between-two-lovers army medic Georgie who overcomes the usual sexism of her male colleagues to win their respect and admiration. That said, the storyline's clichés and coincidences over-abounded, detracting from the striven-for realism, which no amount of irritating army-talk - "Boss" this and "ASAP" could bring off.
It felt like two stories joined together, part one involving Georgie's capture and rescue, the second the search for the returning terror suspect in Manchester. Unfortunately it was all too easy to see the join and this deficiency apart, the leading actors didn't exactly inspire me to praise their efforts either. The twist at the end was okay, but the last episode really dragged up to that point.
In trying for a realistic, accurate depiction of army life ing hostile foreign environments, this series never really made me feel like I was there.