"Strike Three" is the 1007th episode of Casualty and the third episode of the 31st series. It was preceded by "Fall on Me" and followed by "Pride Comes Before a Fall". The episode was directed by Seán Gleeson and written by Claire Miller. This is the second occurrence by which the third episode of a series has the word "three" in its title, the first being series 24's "And Then There Were Three".
Connie remains at Grace's bedside, but falls asleep due to her lack of rest. During which, she has a dream that Jac Naylor performs an operation on Grace which kills her. She's awoken and surprised to see Sam also at Grace's bedside, having flown over from the US when he heard the news. However, when it's discovered that Grace has a small tear in her aorta, Jac is called down from the wards to carry out the procedure which could put even more of a strain on her brain. Connie is initially apprehensive about letting Jac operate on Grace, believing that the dream could have been some sort of premonition. Despite her doubts, she eventually allows Jac to operate and the surgery is a success.
Following the surgery, Connie speaks with Sam and tells him how she blames herself for what happened. Although she was initially dreading the fact Sam had arrived, he shows some uncharacteristic sympathy for Connie when he realises how she's been affected too. Meanwhile, Elle continues to lead the ED team, although their thoughts are still with Connie and Grace. Duffy has her first official shift in the ED as a permanent staff member since 2003.
An elderly couple are admitted after lightning strikes their house and the husband is electrocuted and later falls through the roof of a conservatory. Whilst docking the ambulance, Iain accidentally hits the wife with the door. At the ED, she suffers from a broken rib and pneumothorax which prompts Lily to pay Iain a visit at the ambulance station. Lily suspects he's not well and persuades him to be re-examined. She helps him see that he doesn’t have to be Mr Action Man all the time, and a strange friendship is born between them. She later stops by the ambulance station to visit Iain, and it's clear that there could be more than one way for their relationship to go. Iain decides to take some time off work to recover.
Robyn is wracking her brain to think of something special to do for Glen. But he surprises her by saying that the thing that would make him most happy is to do all the things that make her happy. She decides to take some time off work and they consider going to Euro Disney. At the end of the day, they all head over to the pub and news of Grace's successful procedure makes it to them. Meanwhile, David tries to make contact with his son Ollie after a chat with Duffy.