It's Christmas Eve in Holby City Hospital and Ruth is determined to have a good Christmas, despite the precarious state of her marriage. When she finds a present – a badge that reads "No. 1 Doctor" – she assumes it's for her, but then Edward's ex, James, shows up at the ED wearing the badge. Realising that Edward has been lying all along, Ruth issues him an ultimatum. Will the two doctors spend their first Christmas in harmony or will this be one year Ruth doesn't forget in a hurry?
Ruth and James treat young mother Sara, whose sister, Deena, comes into the hospital along with her partner, David. The estranged sisters barely have time to make up before Ruth and James clash, causing a fatal mix-up with Sara's drugs.
Meanwhile, Kirsty is struggling to work alongside Adam after she told him last week that nothing more could happen between them. Adam spends all day trying to help her out but she refuses his assistance at every turn. Is Kirsty able to put her personal feelings to one side for the sake of their professional relationship?
Mads is missing home. She's also trying to understand why everyone seems to be miserable or drunk at Christmas. When she meets a patient, Lily, in the Clinical Decision Unit – whom everyone else thinks has been dumped in the hospital for Christmas – Mads holds out hope. With Jordan studying all day, Mads is left in charge and she and Noel throw a Christmas party for all the patients in ED. Will Lily's family turn up and prove to Mads that not everyone is horrible at Christmas time?