DI Neil Manson finds himself investigating a murder when assault victim Danny Sissoulu dies in the conclusion of this special two-part story to launch the new-look Bill at 9pm.

Neil’s prime suspect is Craig Middleton, who he has tucked up at Sun Hill. But Craig isn’t confessing to murder. He says he was innocently walking his baby in the park and was attacked by Danny, his brother Kip and their friend, Mo Campbell. They had a knife and he was slashed. He punched Danny in self-defence.

Danny’s grieving mother Miriam is outraged when she hears all this. Her boys don’t carry knives, she insists. But Kip is very quiet and Neil’s certain there’s more to this. Frustrated by the investigation’s lack of progress, Superintendent Jack Meadows tells Neil to bug the Sissoulu’s home – and to keep the operation secret from DC Jacob Banks, who is acting as Family Liaison Officer…

Meanwhile, Banksy discovers that Danny and Kip were actually involved in an anti-knife campaign and tells Neil he should leave the family alone. But Neil’s already watching the Sissoulus. His surveillance catches mum and dad telling their daughter to delete incriminating evidence from a computer and reveals a different family story.

When the officers question Mo, the boys’ friend, they finally discover the shocking truth about what happened in the park.