A woman named Miranda secretly pursues a man named Eddy and accidentally crashes into him. At the ED, after two CQC inspectors arrive, Charlie tells Robyn that there is a shortage of nursing staff and asks her to help out. Robyn does not have a child minder for Charlotte, so Charlie suggests that Duffy looks after her. Effie tells Ethan that she is unphased by the revelation that he has Huntington's disease and tells him that, if she only has a few "good" years left, she is going to "grab all the good things" while she can, including him. Robyn is unsure about allowing Duffy to look after Charlotte, but Duffy assures her that they will stay at home. After Rash returns from his week of leave, he and Ethan make amends, and Dylan warns Rash that he is on final notice. Ruby and Lev arrive at the scene of the road accident, and Miranda insists on accompanying Eddy to the hospital.
After baking cupcakes with Charlotte, Duffy notices that the weather has improved and decides to take her to the park. Ethan gives Effie a key to his home and suggests that she factor in future treatments while considering the rest of her life; Effie accepts the key but claims that she will not participate in any more trials. While at the park with Charlotte, Duffy's mind goes foggy, prompting her to leave without Charlotte. Confused and frightened, she tries to call Charlie, but he does not answer. Duffy walks to the ED and is relieved to see Charlie, but Robyn demands to know where Charlotte is. After Eddy is taken into the ED, Archie prepares to relocate his open tibial fracture, but Eddy refuses pain relief and explains that he is a recovering addict.
Robyn blames herself for leaving Charlotte in Duffy's care and goes to search for her daughter. Charlie urges her to stay in the department, but Robyn dismisses him. In cubicles, Miranda tells Eddy that she was his maths teacher and claims that she remembers as a "very smiley, very happy little boy". Meanwhile, Charlie and Duffy realise that the latter's condition is worse than they originally thought. Miranda reveals to Ethan that she is actually Eddy's biological mother and explains that she was planning to meet him. While treating a man named Aidan Durrell, Rash realises that he is completely deaf in one ear. After Effie expresses an interest in a house share, Ethan questions if she is "rushing" into it, but Effie contends that she has very little time left to have that experience. Elsewhere in Holby, Robyn desperately searches for Charlotte but quickly begins to lose hope. Miranda finds out that Eddy has been stealing credit cards; Eddy explains that he had a difficult time in care and asks her how old he was when he was "happy".
Robyn returns to the ED and is mortified to learn that an unnamed three-year-old girl is being taken in after getting hit by a motor vehicle. A heartbroken Miranda regrets not keeping Eddy and fears that he will hate her if she tells him the truth, but Ethan reassures her and urges her not to give up. After Robyn identifies the girl as not being Charlotte, she demands to see Duffy's phone and recognises the park in one of the photos Duffy took of Charlotte. In pain, Eddy begins to believe that he cannot stay clean; Miranda holds his hand and tells him that she believes in him. Robyn and Charlie arrive at the park, and Robyn is relieved to find Charlotte. Dylan informs Rash that Aidan has a tumour in his ear and demands to know why Aidan has breached; Rash manages to successfully lie to Dylan about already formulating a diagnosis and ordering an MRI. Ethan tells Miranda that she has cervical myelopathy and needs surgery. Miranda decides against telling Eddy that she is his mother, believing that it might negatively impact his rehabilitation, and bids him farewell.
Upstairs, Ethan tells Effie that he is not going to accompany her on her adventures because he is not spontaneous by nature and likes her too much to "hold [her] back". Rash and Mason inform Aidan that he has an acoustic neuroma and should undergo surgery to have it removed before it grows larger enough to press against his brain stem, but Aidan takes issue with the doctors asking about his living situation and leaves. Duffy apologises to Robyn for losing Charlotte and explains that she experienced a "thick fog" that she had never felt before. Rash follows Aidan and manages to convince him to accept treatment. Robyn confronts Charlie, and argues that he knew how bad Duffy's condition was and yet did nothing to stop her; Charlie insists that Duffy still has "good" days and dismisses the idea of finding someone to talk to about his struggles. Rash tells Dylan about Aidan's treatment and tries to reassure him that he is working towards becoming a better doctor, but Dylan just tells him to go home. Robyn tells Charlie that she let Charlotte down and states that, from now on, it is just her and Charlotte.
- Amanda Henderson as Robyn Miller
- Derek Thompson as Charlie Fairhead
- Cathy Shipton as Lisa "Duffy" Duffin
- George Rainsford as Ethan Hardy
- Neet Mohan as Rashid Masum
- Victor Oshin as Mason Reede
- William Beck as Dylan Keogh
- Jason Durr as David Hide
- Gabriella Leon as Jade Lovall
- Jack Nolan as Will Noble
- Maddy Hill as Ruby Spark
- Tony Marshall as Noel Garcia
- Uriel Emil as Lev Malinovsky
- Genesis Lynea as Archie Hudson
- Abigail Hardingham as Effie Laurence
- Emma Beattie as Miranda O'Brian
- Daniel Kendrick as Eddy Colins
- John MacKay as Aidan Durrell