HUNDREDS of people visiting Lincoln Castle walk past the grave of Priscilla Biggadike every day – but now her tragic story is set to become a musical.Priscilla was hanged at the castle in 1868 for the murder of husband Richard at their home in Stickney, near Boston.She was buried in the castle's Lucy Tower, but years after her death, her lodger confessed to the crime.Priscilla lived with her husband Richard in a two-bedroom house with two children and two lodgers. She was hanged for murder after allegedly putting arsenic in a cake. When she was incarcerated, she said she'd seen one of her lodgers do it, Thomas Procter, who was a rat-catcher by trade.She retracted that statement and was convicted of hanging on circumstantial evidence.There was no real proof but the jury convicted her.After she was hanged, Thomas Proctor confessed on his death bed to the murder of Richard.