In the first episode of series, Paul meets five-year-old Daniel who has been in the hospital for a month unable to walk properly after banging his knee whilst playing at home. Just after his accident, Daniel began struggling to walk and he was diagnosed with a rare type of arthritis.

In the second episode Paul meets 13-year-old Lola who has been in hospital for four weeks after being diagnosed with Juvenile Dermatomyositis which has caused inflammation of her muscles and skin. When Paul meets Lola her muscles are so weak and she can't walk, but her mum explains that just six weeks earlier she had been fine. The condition affects one in a million people and Lola needs physiotherapy to help her. Paul is there when Lola tried to take some steps for the first time in two months. Also in the programme, Paul meets ten-year-old Oscar who has Tourette's. Oscar mostly has motor ticks, which means he sniffs and coughs. He explains that it's a human glitch which causes him to have involuntary movements. But he tells Paul that after developing Tourette's he became too anxious to leave the house.

Paul hears the story of six-year-old Noah, who was born with a genetic disorder that affects the body's organs and has been referred to Great Ormond Street for the removal of his kidney, which stopped working a long time ago. The presenter also meets a couple of two-year-olds - Lucas who has a detached retina and needs laser surgery on his eye and Taylor-Rose who has accidentally swallowed a watch battery.

Paul meets energetic five-year-old Cora, who has cerebral palsy. To try to improve her co-ordination and muscle control, Cora is having Botox injections in her leg as part of a pioneering research trial. The presenter also chats to 10-year-old George, who is at the hospital for the latest round of laser surgery to lessen his facial birthmarks, and hears about three-month-old Oliver, who was born with a cleft lip. Oliver is just one of 6,000 babies treated at Great Ormond Street every year, so Paul also meets the special team dedicated to meeting the feeding demands of all those hungry little mouths.

Paul meets 13-year-old Noah, who has checked into the neurology ward ahead of an operation to correct a structural defect of the skull. The youngster needs to overcome his anxiety, however, so Paul joins him on a fun tour aimed at demystifying surgical theatres. Other children include seven-year-old Oliver, a long-term patient who is struggling to walk after being struck down by arthritis, and 17-year-old Rue, who has lost much of her sight and is now using various gadgets to re-learn many everyday tasks.

Paul meets charming four-year-old Lucy, who has travelled down from Glasgow for the latest check-up to monitor her pulmonary hypertension - a high blood pressure condition that affects the lungs. He also meets remarkable 13-year-old Connor, who is on the isolation ward as he prepares for a bone marrow transplant to help treat leukaemia. As Connor needs to live in a totally sterile environment to protect his weakened immune system, Paul can only speak to him through a window - but that doesn't stop him finding a number of fun and interesting ways to keep Connor occupied during his recovery.