"Party Pooper" is the 1010th episode of Casualty and the sixth episode of the 31st series. It was preceded by "Schoolboy Crush" and followed by "Too Much Love Will Kill You". The episode was directed by Diarmuid Goggins and written by Rachel Aird. The events of this episode take place on 19 September 2016.
Jez and Max wake up next to each other following Alicia's prank the night before. Confused at what has happened, they're not helped by Alicia who only makes their suspicions that they slept together increase. Max is due to spend a day observing with the paramedics, but as Iain is only on administrative tasks following his injuries and time off, the duo are forced to work together for the day.
Jacob arrives, nervous for his interview with Henrik regarding the clinical nurse manager role. Elle assures him it'll be fine. Following the interview, Elle is informed that he's got the job but decides to have some fun of her own and decides to tell Jacob she doesn't know, leaving him on edge all day.
Meanwhile, Gaynor is re-admitted to the ED, the woman who'd recently been brought into the ED after a fall down a woodland cave. This time, she's fallen through the glass pane wall of a greenhouse and suffered from a deep arm laceration. She's brought into the ED and is treated by Ethan, who soon starts to notice her lapses in memory and suspects that she could be suffering from something more severe.
It's also Alicia's birthday and Ethan is busy preparing for her party that evening. Despite this, he overhears her say she's enjoying being single and informs her that he won't be able to make it. However, little does he know she only said it because she assumed that she's ruined her chance following her drunken incident.
Elsewhere in Holby, Jez and Max are called out to an accident at a strip club where one of the dancers, Lisa (stage name Sambuca), has accidentally stabbed a man, Henry, in the chest with her stiletto heel. Only once they're back at the ED does it transpire that he's her father and is looking to reconcile with her after changing his bad ways. However, she's having none of it and ignores her now-vicar father. Lily attempts to intervene and make Lisa accept her father's offer for help.
In reception, Alicia slyly tells Lily that her party is fancy dress in an attempt to deter Lily from coming, which she seemingly does successfully. Lily goes outside to find that Lisa is on the phone and is having money problems, prompting Lily to pressure her to reconcile with her father. Lisa still ignores her, but when her dad begins suffering from breathing difficulties and complications from his earlier wound, she shares a chat with Lily in the chapel. Lily tells Lisa that it's the one year anniversary of her father's death.
Meanwhile, Ethan looks deeper into Gaynor's condition and finds from her earlier CT scan that she has early symptoms of dementia. She's initially reluctant to tell her husband Daniel, but when Ethan opens up to her about his Huntington's she agrees to get treated. Ethan carries out an exam on Gaynor and explains that her short term memory could start becoming worse. Daniel pledges to stay by her side.
Lisa apologises to Lily for her harshness earlier in the day and when Lily reconsiders going to Alicia's party, she decides to go in Lisa's stripper outfit. Leaving for the pub, Alicia admits the truth to Max and Jez to their relief. Alicia is shocked to discover that Ethan has ordered in a load more balloons for the party and although she thanks him, he still says that he's unable to go. Lily arrives at the pub in the pole dancer costume and is mortified to find that no-one else is in fancy dress. However, she seeks comfort from Iain who compliments her and puts on the feather boa.
Ethan sees Gaynor who encourages him to go to the party as he'd told her that he was going to seize every moment. Ethan arrives at the party but turns away when he sees Alicia kissing Cal through the window.
The episode received mixed responses following its transmission. Alison Graham from the Radio Times reviewed the episode, saying "Sadly, Casualty has joined the growing List of Shame by featuring a tawdry scene in a pole-dancing club, when a dancer has a bloody encounter with her desperate dad."
Many fans took to social media to share their opinions on the episode, with many voicing their dislike for Cal after he kissed Alicia. Despite this, the scenes where Lily attends the party were well received and "added much needed humour to the episode". Still, this too left fans feeling sorry for Lily and even resulted in some noting that they'd seen a new side to Alicia.