Keelin has to face up to the news about her mother's cancer. She realises that her family cannot cope and she has to give up her single lifestyle and move back home to care for Mary, a difficult woman whom Keelin has never got on with at the best of times. Fiona goes further off the rails, and Cathy is forced to dismiss her.
Alex considers starting a thing with local barman, Michael. His carefree existence is abruptly shattered however by a needle stick incident. The thought of contracting Hep C from the needle and having to give up the job he loves turns Alex into an unrecognisable nervous wreck, much to everyone's surprise.
Things are hotting up as affairs start rising to the surface. Paul tells Keelin he knows about her and Ed and begs her not to say anything to Yvonne about his carry on at the stag party. Meanwhile, Cathy tells Ed she might be pregnant and in turn Ed tells Keelin the news, who lets a congratulations slip to Cathy! Meanwhile, Yvonne hears Keelin and Paul fighting about his stag night antics and loses her temper with Keelin and tells her she doesn't want her to be her bridesmaid any more.
Fiona is deeply missing Ed and thinks that The Clinic is falling apart without him. In her attempts to save The Clinic she only manages to make matters worse. Cathy too is feeling the aftermath of Ed's departure and is unable to cope with the daily business.
Brendan's inheritance of his Nan's house worth 2.75 million euro has just become official. The other staff in The Clinic question Brendan on what he would like to do with this money. Brendan is happy with his life and has no intention of selling his beloved Nan's house. Everybody has an ambition except for him and he tries to live his ambition through Clodagh.
Patrick is lonely and everything around him is further illustrating how alone he is. Through a chance encounter with an old acquaintance, he learns that his ex-wife Lisa is in town. They arrange to meet. Lisa hasn't seen him sober in a long time and is surprised by this new man. They get on great, the sparks are flying and their relationship takes a new turn.
Clodagh is very focused in work. She is doing well professionally and has had an article published in a prestigious medical journal. However, she has just moved back home and her worlds are clashing. Events come to a head as she, her mother and father all celebrate her achievement at a posh restaurant.
Keelin has to decide if her business is worth losing her friends. Paul turns up at the Clinic asking Keelin to build bridges with a pregnant Kathleen, she is sceptical at first but is delighted when she arranges dinner with Kathleen. Keelin is furious to learn that Cathy has been referring patients to other physiotherapists.
Richard is struggling to deal with his wife Annie's illness while trying to keep his home and work life separate. His daughter Flossie is devastated when she discovers that she could have the Huntington's gene. Trying to pretend that everything is okay and not accepting help has not worked, Richard finally comes to the realisation that he has to face up to his wife's illness.
Dan is terrified when he realises he could be caught out for dating both Cathy and Sinéad and tries to find a way to prevent them meeting. Dan is thwarted when Sinéad meets Cathy. He tries to talk his way out of it by telling Cathy it was her idea to have a no strings attached relationship and as soon as they started to get serious he finished with Sinéad.
Aine finds it increasingly difficult to cope with her son Tommy and reacts in a shocking and distressing way. Meanwhile, Cathy deliberately keeps Julia waiting in reception for their meeting. This backfires on Cathy when Dan invites Julia to dinner and sweet-talks her into taking a more permanent position in the Clinic.
Dan is devastated to discover he has a life-threatening and that the only operation that can cure him may also end his career. He tries to confide his problems to Cathy, but she tells him there is just too much water under the bridge now for them to be friends. Meanwhile, Keelin, with the help of her father, decides to follow Ronan to New York to give their relationship a second chance.
Patrick refuses to take an agitated Conor for a session after Conor is rude and insults Bernie. Clodagh has had enough with her acupuncture patients and tells Julia she would like to concentrate on her general practice. Daisy is clearly uncomfortable around Jack and calls him a creep under her breath. Cathy is puzzled by the way Dan is acting and agrees to meet him for lunch. Liam teaches his son, Ian, a lesson after he had a few beers and fell over drunk. Ann Marie teases Jack about Clodagh fancying him but Jack tells her she has nothing to worry about.
Daisy thinks she may have been a cause of Conor's break up with his girlfriend, Siobhann, as well as his accident, after Siobhann warns Daisy to stay away from him. Cara tells Daisy that she didn't give Conor the wrong signals. Patrick reassures Daisy she's not to blame for what happened with Conor and needs to talk to him. Daisy talks to Conor and is relieved his self harming had nothing to do with her.
Dan is back with a second chance after surgery but his life is thrown into turmoil when he discovers Cathy is pregnant. It's a tumultuous start for the couple but they finally come together as one and look forward to their future. Cathy is now monitoring Clodagh's every step after her potentially life-threatening diagnosis and this causes tension for Clodagh. Daisy moves in with Conor and starts a relationship with Adam.
Liam's son Ian wants the morning after pill for a girl he had unprotected sex with but, when Liam calls her parents, he is stunned to hear that she claims Ian raped her. Meanwhile, Keelin returns to The Clinic from the U.S. a married woman. Julia's ex Harry arrives back on the scene and Ed changes his mind about selling his half of the building to Cathy and puts it on the market.
Julia is tempted by her ex-husband Harry's overtures to win her back - until she discovers that he has cancer. Dr. Lorcan O'Brien buys Ed's half of the practice and building which annoys Dan. Dan finally goes back to work at the Vico and repairs a knife wound scar on Keith Reid.
Clodagh's birth mother Carol comes to see her with news that her husband Tom is on the warpath and looking for Clodagh's father, Frederick - the man he believes to be responsible for ruining his life. Upset, Clodagh turns Carol away but later at The Clinic Tom shows up and won't leave until Clodagh hears him out. He becomes physically threatening and Lorcan has to step in to remove him from the premises. Carol returns to beg the shaken Clodagh not to get the Gardaí involved and, while Clodagh agrees to this request, she decides its best not to talk to Carol anymore.
Daisy's close friendship with Conor seems increasingly difficult for Adam to accept. But how will Daisy react when Conor admits that he is in love with her? Meanwhile, Cara marks some notes in the petty-cash box with nail polish to get to the bottom of who is stealing the cash. Elsewhere, Dan has another run-in with new doctor, Lorcan, over one of his methadone patients. Paul discovers he has Peripheral Arterial Disease (PAD) - a clogging of the arteries that could cause a heart attach at any time - a diagnosis that causes dis-harmony in Ronan and Keelin's ...
Liam dramatically kicks Cara out of the house when he finds out that she gave his son Ian's girlfriend Lucy the morning-after pill. Clodagh and Keelin are not on speaking terms because of Paul Dunne's legal action against Clodagh. Meanwhile, Cathy diagnosis Cara's friend Mary with clinical bulimia. Elsewhere, Aine is accused of taking petty cash causing her to step down as practice manager. Lorcan eventually finds out that the petty-cash culprit is actually his sister Alice who is back using again.
Daisy and Cara vie for the position of Practice Manager, while two suitors - Conor and Adam - compete for Daisy's affections. Meanwhile, Dan has an uncomfortable run-in with Emer - his nearly one-night stand - outside the Clinic and finds out that she is one of Lorcan's free-clinic patients. Elsewhere, Patrick asks Bernie to move in with him.
Bernie moves in with Patrick, but she soon realises that he isn't ready to co-habit. Meanwhile, new practice manager Cara struggles to cope without a receptionist and Kieran cannot cope without Molly and leaves baby Hope with Cathy. Elsewhere, Dan and Cathy look at a property in the country and Emer has delusions over her relationship with Dan.
Lorcan's sister Alice, who's back using drugs again, begs Lorcan to help her go 'cold turkey'. Although Lorcan knows it's ethically inadvisable to treat his own sister, he reluctantly agrees to help Alice - on condition that she be locked in the flat. No-one at The Clinic can find out what they are up to. Lorcan is so preoccupied with keeping the whole thing quite that he prescribes the wrong medication to a patient with almost disastrous results, not to mention what happens when Alice collapses at the reception desk.
Cathy continues to lie in a coma after being run over by Niall Boylan unaware that she lost her cherished baby girl - Rachel - in the accident. Liam's son Ian is in trouble yet again and gets expelled from school and Liam has no choice but to put him into a fee paying school. Daisy returns home with Conor to be at Cathy's bedside and is there when Cathy suffers a brain haemorrhage and dies.
Dan's grief over Cathy's death is overshadowed by hearing that Niall Boylan will escape relatively free from a serious conviction. Dan's solicitor warns Dan to stay away from Niall. Meanwhile, new locum Dr Grace Sefate makes an impact on her first day when her belongings turn up before her. This unusual entrance immediately gives Grace an air of intrigue but she immediately asserts herself as a capable and dedicated doctor. Lorcan starts to struggle with his illness, now that he is on a harsh course of anti-retroviral medication for his HIV and this sees him becoming ...
St. Matthew's Hospital Director Michael Kinsella is keen for Julia to take over the job but she declines and tells him she is happy at the Clarence Street Clinic but will she regret her decision when long standing patient of hers Elayne Sheridan discovers she is pregnant for the fourth time and places Julia in an unenviable dilemma. Meanwhiile, Dan continues his thirst for revenge on Niall Boylan through his wife, Aideen and discovers her love of art. Clodagh agrees to help out on the night clinic and the methadone bus and is moved by Lorcan's dedication to his ...
Grace tells Ruairi about her missing sister Jasmine when he finds one of her flyer's on the photocopier. Lorcan asks Dr Kent about getting involved with someone given his HIV status. Keelin notices that a young client's fitness levels have gone through the roof and later he suffers a heart attack brought on by his use of illegal steroids. Ian and Liam agree a truce but Liam's dependence on Rocusin tablets makes him jump to incorrect conclusions about Ian later after he sees Ian's old buddies Phil and Martin outside their house.
Ronan and Keelin's lives are turned upside down when a senseless attack on Ronan by one of Ian's friends leaves him potentially paralysed. Meanwhile, Liam's addiction begins to get worse and cracks begin to appear in Daisy and Conor's relationship as Daisy struggles to juggle her work with her home life. Elsewhere, Cara struggles with what she did to Hope and Kieran.
Liam continues taking Rocusin, and even steals a prescription from one of Grace's patients. After giving wrong medication to another patient, Liam blames Grace and convinces the patient to back up his story. Julia takes Liam's side in the matter. It takes Alice to recognize that it is Liam that is at fault and she goes to Lorcan about his behaviour. After being confronted, Liam admits to his drug abuse and it leaves Julia with no option but to suspend him from work. Elsewhere, Aideen doesn't turn up at the airport and later tells Dan to leave her alone. Later Dan is ...
Alice secures a temporary role as the nurse in the clinic, and is keen to celebrate with Dan. Annie Ward brings her ex-boyfriend, Dave, to the night clinic in an effort to wean him off heroin with disastrous consequences.
Fergus Mitchell, a teenager claiming to be Patrick's son is mugged and beaten up and asks for Patrick when at the hospital.But Bernie doubts his story but Patrick isn't swayed. Elsewhere, Julia agrees to run for job of Hospital Director and when she gets the job she offers her shares to Lorcan and Cara steps in as birth partner to Fiona. Meanwhile, Lorcan and Clodagh decide to go out on a date.
Dan and Daisy face Niall Boylan in court but later find out that he has been killed. After Alice lets slip about Lorcan's HIV status Dan confronts him. Later, Dan is arrested for Niall Boylan's murder.
Dan is questioned by the Gardai over Niall Boylan's death but is eventually released only to incur the wrath of Daisy about his involvement in supplying cosmetic surgery products at inflated prices. Lorcan supports Dan which Daisy doesn't understand but Dan is holding a trump card - Lorcan's HIV status. Elsewhere, Lorcan's daughter Madison moves in with him.
Daisy starts monitoring the Clinic's cash-flow and is less than happy with her findings. Dan takes on the complicated surgery of a young African boy with a deformity that could kill him. Ruairí's dad Franny goes to see Patrick and he encourages him to enjoy his last few months by drawing up a 'bucket list'. Meanwhile, Cara forges a prescription for a long-standing patient but is found out leaving Daisy with no option but to give her a verbal warning. Elsewhere, Dave blackmails Lorcan to giving him cash in return for him staying silent on his HIV status.
Dan is up against the Medical Council for his hearing. Alice is upset when she finds Dan has turned to Daisy for support on the day of his hearing. Dan blackmails Lorcan to be on his side when he is called to testify but will Lorcan comply? Meanwhile, Ruairi helps his dad Franny build a sun-deck for Grace but Franny's condition gets progressively worse but does not tell Ruairi.
Ruairi's dad Franny's condition deteriorates faster and after seeing his old friend Al in the early stages of dementia asks Grace to up his morphine to ease his symptoms so that he doesn't have to depend on Ruairi and Terry. Madison develops a crush on Fergus. Dave continues to use his knowledge of Lorcan's HIV status to get preferential treatment. Meanwhile, Alice becomes jealous of Dan's attention to Daisy. Elsewhere, a striking blonde visiting the Clinic arouses Dan's curiosity. Franny dies in his wife's arms after his big party and Ruairi discovers afterwards that...
Having had his advances turned down by Daisy and having broken up with Alice Dan turns to gambling and meets the mysterious Lucille. Ruairi and Daisy become closer as they paint the clinic's conservatory. Lorcan is brought further under the influence of Dave and ends up dealing with a known drug dealer to get methadone for him. Clodagh's first stint as a medical radio D.J. marks an eventful time for her and a patient she deals with online. Meanwhile, new doctor Dr. Edel Swift has major plans for the clinic, Alice quits as nurse in the practice and Grace has to deal ...
New general surgery doctor Edel Swift deals with a litany of emergencies that walk into the Clarence Street Clinic and Dan is quite taken by her but he is also obsessed with Lucille and even more so when he finds he cheated at poker and she now owns his shares. Elsewhere, Lorcan finds out that Annie has tested positive for HIV and has to break the news to her but the stress of it makes him take it out on Clodagh. As a result of Annie's test Dave turns up and threatens him again with exposure but Clodagh intervenes and tells Dave that he also is HIV and she had him ...
Rumour and speculation spread like wildfire about The Clinic's HIV-infected doctor causing cancellations and panic. Lorcan disappears and it is up to Clodagh to tell Madison about her dad's condition before she hears about it from others - she takes the news badly but in the end she and Clodagh track Lorcan down. Dan tells Daisy that he and Cathy knew of Lorcan's HIV status and asks now that they take action and have him removed from the Clinic before the practice goes under. Dan performs a double mastectomy on a young woman whose family has a chronic history of ...
Dan's last day at the Clarence Street Clinic is anything but uneventful as his nemesis Diarmuid and Lucille arrive at his surgery and demand that he treat a bullet wound that Lucille has received. When things don't go Diarmuid's way he takes the Clinic staff hostage and makes Dan and Edel operate under gunpoint. When Daisy argues with him he hits her forcing Ruairi to attack him which results in Diarmuid shooting him in the stomach. Daisy begs Dan to help Ruairi and although under threat of being shot he brings Ruairi outside and calls an ambulance as the Gardai storm...