When orthopaedic surgeon Clare Carpenter arrives at Cardiff's Noah's Ark Children's Hospital, the day has already been turned on its head. An influx of emergency cases over the weekend mean there aren't enough beds or nurses for all the children who need surgery. Some planned operations will have to be cancelled, something Clare and her team try to avoid at all costs. One of Clare's urgent cases is seven-year-old Olly, who broke his leg at school and was airlifted to hospital. Olly has already broken his femur in the same place once before and needs surgery as soon as possible to stabilise the break. Clare and her team also need to work out what's causing Olly's bones to break more easily than they should. Despite the huge challenges, Clare and her team go above and beyond to get to as many young patients as possible. Meanwhile, in the University Hospital of Wales, neurosurgeon Amr Mohamed and a unique specialist team that treat complex conditions affecting the skull prepare for a nine-hour operation. And ophthalmology surgeon Magdalena Popiela is fighting to save the sight of a mum-of-two with congenital cataracts.