Christine Potts has discovered a lump in her breast, and has been referred to a hospital by her local GP. She undergoes a rather impersonal examination, although the houseman Dr Pearce is much friendlier than the others. The doctors agree that Christine should come in for a biopsy, although they reassure her that there is probably nothing to worry about. Christine is mainly concerned about arrangements for her two daughters when she is in hospital.

Some weeks later, Christine arrives at Ward 20. As Christine settles in nervously, a student called Anna is admitted into the next bed. They are both depressed by the poorly condition of Mrs Scully, an elderly woman in a nearby bed. The nurses gossip while they prepare Christine for the biopsy, and Dr Seal explains the procedure in rather sketchy terms. Christine signs the consent form. Later, her husband Joe visits, and Christine urges him to ask the sister if she will be out of hospital by Friday. Joe is not comfortable with asking, and he bridles slightly at Christine's fussing. As the ward settles down to sleep, a nurse sees Anna taking the contraceptive pill, and realises this will prevent her having her biopsy. The nurse dispenses some sleeping pills to Christine, and tells her to get some sleep for the operation in the morning. Pearce arrives and confirms to Anna that she can no longer have her biopsy, and she dresses and storms out. Christine tries to sleep through the general hubbub of the ward.

The anaesthetist attends to Christine while she is asked by Dr Seal to sign an open consent form in addition to the form specific to the biopsy. She is taken into the theatre, where the Registrar and Staunton, the surgeon, begin the biopsy. They send some tissue for tests and it is confirmed as malignant, so they perform a mastectomy. Afterwards a cheery histologist collects the remnants of Christine's breast.

Christine comes around from the anaesthetic in some distress, as she realises her breast has been removed. Joe visits and is stunned by the extent of the surgery. He is persuaded to go and talk to the Sister, who simply tells him that something nasty needed to be removed. Joe worries about Christine's state of mind. The next day Staunton starts his round. The group of doctors talk about Christine's condition, but don't interact with her. Later she has some physiotherapy, and a bath, although they have to be careful to avoid getting the wound wet. Dr Seal visits Christine, and she expresses her concern about Staunton's round. He tells her not to worry. She would like to see Dr Pearce, but Dr Seal thinks it is his day off. The visiting period starts, and Christine's mum arrives.

During the night, Christine locks herself in the patients' toilet. The nurses try and persuade her to come out, but she stays silent and won't move. By chance, Dr Pearce returns to the hospital after a night out drinking. He appropriates a ladder and tells the nurses to fetch him a wheelchair. e leans the ladder against the cubicle wall in order to talk to Christine, and, after persuading her to come out, takes her to his room in the wheelchair to make her cocoa. She expresses her dislike of the way she has been fobbed off by doctors and generally treated like a child. She wants to know what she is facing. Pearce confirms that she has cancer, and that some of her lymph nodes were also affected and removed. At length he explains that the medical profession has forgotten its obligations to communicate clearly with the patients, and that people like Christine have to demand their rights to be treated like a human being.

Christine has the stitches removed, and is now able to look at her wound. Anna returns to the ward and is shocked to hear about the mastectomy, but Christine seems more resilient and reassures a worried Anna about her biopsy. That night, Anna wakes Christine, and they share a large bottle of gin with Mrs Scully and some others. The women share a toast and a giggle in the dark ward.