Teenaged twins Alan and Brett Cameron [originally seen in episode 1.39, although not by these actors] suffer from cystic fibrosis and have been on a long waiting list for lung transplants. Their overall health has deteriorated recently with Alan bedridden at home with pseudomonas. Brett has the same condition but is not quite as acutely ill as his brother. Alan has been brought on to Ward 17 for treatment. The staff know Alan and his brother very well — they have been regular patients at All Saints all their lives, and they are extremely well-informed about their cystic fibrosis and its complications. The twins are bonded in age, temperament and, most of all, their illness. Now, for the first time in their lives, they are going to be separated by something they never anticipated: good health. When a lung transplant becomes a possibility, one of them will have a ticket to health, leaving the other behind. This creates feelings of guilt, isolation and bitterness they never anticipated.