In this episode, Paul meets 13-year-old Mackenzie, who was born with microtia, a condition that meant his left ear was underdeveloped. He also meets brother and sister Emily and Luke, who were both born with cystic fibrosis, and gutsy nine-year-old Lara who has a blood disease that has affected her since she was a baby.

In the second episode of series, Paul joins eight-year-old patient Lily for a scoot around the hospital corridors. Lily was rushed to GOSH three months earlier with severe pain in her thigh. After a week of tests she was diagnosed with a rare and aggressive form of leukaemia.

In the third episode of series, Paul meets 11-year-old patient Fazeel, who suffers from a rare condition known as EB, which effects just 5000 people in the UK and currently has no cure. Fazeel's condition means he has delicate, painful skin and also needs regular eye checks to look for damage or blistering inside the eye.

Paul meets 13-year-old Amelie, who has been coming to the hospital since she was a baby with a very rare case of juvenile idiopathic arthritis. Meanwhile, Paul also meets eight-month-old Alexander, who was born profoundly deaf, and three-year-old Esme, who has a complex heart condition which means she has been receiving treatment in the hospital since she was 11 months old.

Paul first meets three-year-old Angel, who is a regular visitor to Eagle Ward, Great Ormond Street Hospital's kidney centre, as she needs dialysis while she waits for a new kidney. He also meets 11-year-old George, who had life-saving open heart surgery at GOSH when he was just eight, and since then comes back twice a year for a series of critical cardiology tests to find out whether his condition has deteriorated.

In the final episode, Paul meets a young girl suffering from a very rare bone infection, and is on hand to keep her spirits high as she begins her recovery. Paul also meets four-year-old Rosey, who is coming out of the hospital after her 17th operation, before visiting 14-month-old baby Amelie, who has been living in the hospital since she was born. Last in the series.