Holby City Hanssen is introduced as the new joint Director of Surgery at Holby Hospital, working alongside
Connie Beauchamp (
Amanda Mealing). In a meeting with the hospital board, he criticises Connie's plan to purchase a new
MRI scanner for the cardiothoracic ward as being self-serving and naïve. He later informs the staff that budget cuts and redundancies will have to be made for the good of the hospital in a fraught economic climate. Hanssen considers making general surgeon
Ric Griffin (
Hugh Quarshie) redundant as he is unable to perform clinical duties while undergoing chemotherapy. Connie defends Ric's position, and Hanssen allows her to make the final decision on redundancies, resulting in the dismissal of six nurses. Hanssen later grants Ric leave of absence to concentrate on his health. Before departing, Ric requests that Hanssen direct his budget cuts away from the general surgery department. After Connie's resignation from Holby City at the start of 2011, Hanssen becomes the sole Director of Surgery. He also assumes the position of CEO following the resignation of Mark Williams in January 2011, merging this role with his Director of Surgery duties. In March 2011, after attempting to move all Upper-GI surgical cases from Keller ward to St James' Hospital, undermining Ric in the process and causing Ric to form a mutiny with fellow members of staff, Hanssen offers to operate on Ric in a risky bid to remove his terminal cancer. Henrik's friendship with
Sahira Shah (
Laila Rouass), whom he hires to Darwin Ward in early 2011, is frowned upon by many of his colleagues, who believe that he is favouring her. Sahira is able to make Hanssen see the error of his ways several times and seems to calm him. Her relationship with
Greg Douglas (
Edward MacLiam), another Darwin surgeon, leads to conflict between the pair, and the belief that Hanssen has feelings for Sahira. When the affair between Sahira and Greg comes out, Sahira leaves the hospital, and it is revealed Hanssen feels like Sahira is a daughter to him and is distraught by her departure.
Serena Campbell (
Catherine Russell) is hired as a new consultant on Keller Ward, and Hanssen finds himself trapped between her and Ric for several episodes. Later on Hanssen agrees with Serena's non-referral scheme and decides to pilot it. When Hanssen's decision costs a patient his life, the patient's unstable son takes Hanssen hostage; however, the scenario makes Hanssen realise that the NHS' current system is wrong and he campaigns against it. In the following weeks, the pressure from the board and the doubt cast by his colleagues causes Hanssen to depart Holby suddenly and without notice; Serena, and then
Imelda Cousins (
Tessa Peake-Jones), take up the position of temporary Director of Surgery. Following Serena's bidding,
Jac Naylor (
Rosie Marcel) tracks Hanssen to Sweden. It is revealed that Hanssen disowned his father Anders Lövborg many years ago, due to Anders using data collected by the Nazis in his scientific research, which Hanssen believes was what led to his Jewish mother Elizabet's suicide. Hanssen then finds out that Elizabet wanted Anders to use the data so that her brother's death in the Holocaust wouldn't be pointless, and that the true reason she committed suicide was because she thought Anders was dead after his disappearance and she couldn't live without him. Now knowing the truth, Hanssen forgives his father and reunites with Anders on his deathbed. Hanssen agrees to return to Holby, to Serena's anguish, and quiets the board by making Serena his deputy. Hanssen becomes close to F1
Tara Lo (
Jing Lusi). When he discovers that she is practising with a brain tumour, he warns her that, if any growth occurs in the tumour, she will have to stop practising with immediate effect; Tara later begins to notice signs of growth but keeps it a secret. Hanssen organises CT scans to which she refuses to go to but later her boyfriend
Oliver Valentine (
James Anderson) finds a recent CT she had and informs Hanssen who tries to pull her out of theatre. Later he shows her the scan which confirms a 20% growth and with the support of Hanssen, Tara agrees to surgery to remove a large amount of the tumour but following complications in theatre she is pronounced brain-stem dead leaving Hanssen deeply upset. Hanssen mellows as he returns to the more hands on side of medicine, spending more time treating patients on the wards and developing his working relationships with colleagues. Hanssen departs Holby General quietly after turning over the role of CEO to Serena. Hanssen returns to Sweden where he reconciles with Maja Johansson (Pia Halvorsen), his former partner, and finally meets his son, Fredrik, and his newborn grandson. Over twenty months later, Hanssen's successor
Guy Self (
John Michie) steps down from the position and orchestrates a plan to bring in a new CEO who will persuade the board to fund his vision of a new neurology centre. Realising that Guy is manipulating both her and the board for his own ends, Serena takes action and makes a call to Hanssen who ultimately decides to return to Holby and takes the vacant CEO position. A rivalry develops between Hanssen and Guy, while he also shows his disdain towards
Dominic Copeland (
David Ames). Hanssen agrees to dress up as Santa so the children at the hospital are not let down after the hired Santa does not show up. Hanssen's son Fredrik arrives at the hospital and clashes with his father. After weeks of arguing, Fredrik leaves but later returns with a gun, killing
Raf di Lucca and severely wounding
Oliver Valentine and
Jac Naylor. Hanssen, along with the police, confronts Fredrik, who is then shot and dies. After Raf's memorial, Hanssen's mental health deteriorates and he takes a break from the hospital, calling on Serena who returns to Holby and takes charge in his absence.
Roxanna MacMillan tells Hanssen that he should not be torturing himself, but he still takes responsibility for Fredrik's actions. Weeks later, Hanssen returns to the hospital and resumes his role as CEO. He visits Ollie, who asks where he has been. Hanssen gets angry at the idea of Ollie trying to retrain and return to work, and tells him that his brain has been damaged. Hanssen goes into theatre to perform an operation with
Meena Chowdhury,
Sacha Levy and Dom, while Ollie is taunting him. After surgery, Hanssen shouts at Ollie again. Meanwhile
Fletch is refusing to write the proposal for Hanssen. Hanssen and Fletch argue. Hanssen pins him up against the wall all while Ollie is watching. Hanssen bursts into tears and Ollie recollects Jac saying that he should stay and become a Consultant and how he took the bullet. Hanssen goes out on to the main ward and starts crying again and Ollie comforts him. Hanssen goes back to theatre, telling Sacha that he cannot be CEO anymore. Hanssen continues to work at Holby as a consultant surgeon and is replaced as CEO by Abigail Tate, an old friend of Serena's. During this time suspicions are aroused over the ethics of his old friend
John Gaskell and his subsequent medical trials. When the truth about Gaskell was exposed Abigail abruptly left and Hanssen assumed the role of CEO once more, but in the fallout of Roxanna's murder and John's death, he began to question whether he was suitable to lead Holby anymore.
Casualty In February 2011, Hanssen visits the Emergency Department downstairs (as seen in
Casualty), in order to observe the work there. He clashes with Lead Consultant
Nick Jordan (
Michael French), prompting Hanssen to instate a new Joint Clinical Lead, in the form of Miriam Turner (
Cheryl Campbell), Jordan's old mentor. Off-screen, Hanssen promotes
Zoe Hanna (
Sunetra Sarker) to the emergency department's clinical lead. When he returns to Holby, Hanssen briefly takes charge of the ED while Zoe and Connie are absent.
Robyn Miller (
Amanda Henderson) and
Ethan Hardy (
George Rainsford) dislike his presence, especially when he appears suspiciously. Hanssen later sits in on the interviews for a new Band 6 Staff Nurse position in the ED, which
Ben "Lofty" Chiltern (
Lee Mead) eventually wins, and is present when Lofty is questioned over the accidental death of an agency nurse. ==Development==