Three and a half centuries after the Household Cavalry was founded, the first female trooper is about to join the regiment. We follow Trooper Nina Crocker as she gets ready to make military history by serving alongside the long serving cavalrymen. While things are getting even tougher for the new recruits, they are entering the next level of training in which the pressure is massively turned up. With very little sleep from working 18 hour days, and under the record-breaking summer heat, they need to survive rigorous inspections to make it to the next stage. Meanwhile, the armoured side of the regiment have travelled to Canada, to practise their fighting skills on the British Army's largest and most unpredictable training ground.