With the third and final series of The Split set to launch in little over a week (Monday 4 April), the BBC have dropped a revealing sneak peek that teases some of the drama in store for fans.This includes new romances, plenty of arguments and a rough ride for protagonist Hannah Stern (Nicola Walker).The fast-paced trailer shows Hannah crying to mum, Ruth (Deborah Findlay), saying: "He wasn't supposed to fall for someone else." To which, Ruth replies: "Why can't they ever just stick with meaningless sex?" From what we can gather, it appears both Nathan and Hannah will turn their romantic attention elsewhere as Christie (Barry Atsma) returns and Nathan lights a spark with newcomer Kate (Sherlock star, Lara Pulver). Get exclusive celebrity stories and fabulous photoshoots straight to your inbox with OK!'s daily newsletter.The trailer shows that there are prickly encounters a-plenty between Hannah and Nathan in the upcoming season, making it clear that the once rock-solid couple are not doing so well at uncoupling.