This week at Liverpool's Alder Hey children's hospital, five-year-old Alan is treated after jumping out of a window, a baby who swallowed turpentine, and a boy who has had an aerosol paint can explode in his face. Also, casualty nurse Mark keeps an eye on his nine-year-old son David during an asthma check-up, and five-year-old Nikita starts chemotherapy treatment for her cancer.