This episode focuses on patients whose illnesses prove tricky to diagnose. Nine-year-old Tino is rushed to resus after slumping over her desk at school. Usually a lively young girl, she can't remember what day it is or her surname. She doesn't even recognise her own mum. Consultant Liz is concerned that Tino is displaying the symptoms of encephalitis, a viral infection that causes swelling of the brain and that can have devastating consequences. In majors, 45-year-old Karen is experiencing numbness down her left side and needs a scan. But it soon becomes clear that Karen's condition is more complicated than it first appears. Karen's been told by various doctors over the years that her issue isn't physical, but psychological, but she won't accept it. Meanwhile, 11-year-old Bailey has been brought to King's after he was run over outside school by a slow moving car. He's broken his leg and has cuts to his face and body and has to endure the excruciating pain of having his broken leg physically re-straightened before it can be pinned.