"Internal Inferno - Part One" is the 227th episode of Casualty and the 1st episode of the 13th series.
Charlie deals with an aggressive patient, Hannah, who wants an abortion. She later leaves, abandoning her daughter Cassie. A young man, Nick, pretends to be ill so his friends can steal from the hospital, but after they have left he really does feel ill. New nurse Chloe Hill looks after Bonnie, who has a cut face, and finds her hiding in the toilet after her husband Richard shows up. Sam and new consultant Max Gallagher try to treat a baby brought in by Jasvir, an Indian woman with no English. They ask British Asian bed manager Adam Osman for help but he only speaks English. They eventually realise the baby has carbon monoxide poisoning. Amy tells Sam and Sunny she and Keith have broken up. George and Mark have also broken up. Headteacher Hiberton tries to question Andy Horne, the father of troublesome pupil Murray, but backs down. Teacher Liz refuses to teach Murray, who threatens classmates Joe and Keeley with a knife. Joe hides in caretaker Sterling's cupboard, where a discarded cigarette sets a sofa alight. Supply teacher Andrea finds Sterling has locked the fire door and tries to shelter her class including Murray and Andrea; Joe also tries to get a lost girl to safety. Josh and Penny find Liz buried under rubble. Tina calls Cassie's father Gary to pick her up, but as he enters the car park Nick's friends, who are carrying him, step out in front of his lorry and he crashes into the police car containing Mark and nurse Julie Day.