At the end of the last series Zoe had just come through pioneering surgery to transplant one of her chest muscles into her arm. The programme follows her over months of physiotherapy to see whether the operation has worked. Born with spina bifida, all through primary school Emily has been happy to wear pull-up nappies. Now Emily has decided to go ahead with the major surgery that doctors have told her is the only way to regulate when she goes to the toilet. Nathan spent his primary years spent in mainstream schools, but now his parents must decide whether inclusion is still best for their son, who has Down's Syndrome. Last year Hamish and his parents moved to the South Island of New Zealand. Hamish had to leave the friends he had grown up with and adapt to a new school where his achondroplasia (or dwarfism) would not be so familiar. At school he became the centre of attention for a few weeks.

The children are now one year older, and some are striving for more independence. Zoe starts to take charge of her own future and surprises her mum by deciding whether or not to go through further surgery on her arms. As William's behaviour starts to deteriorate further, his parents begin the search for answers. Only a detailed MRI scan can reveal if he will need to go undergo brain surgery for the second time in his life. And with Shelbie continuing to require 24-hour care, seven days a week, just to keep her alive, her parents are forced to rethink the way they look after their daughter.

With all six children having reached 10, the families reflect on just how much life has changed over the past decade. Having spent a year working at building up the new muscle in her arm, Zoe finds herself back in theatre for more reconstructive surgery, but this time she has decided that it is going to be on her right arm. Having got to grips with a whole new world of procedures that will allow her to go to the toilet on her own, Emily gets the chance to reap the rewards of her operation, and goes on her first overnight school trip away without mum and dad. And after months of relative stability, Shelbie is admitted to hospital once again. The search begins to find out what is making her so unwell.