Mary was then imprisoned in Loch Leven Castle, which was said to have been the reason for Darnley's death, but escaped a year later ("Mary Stuart, Queen of Scots" par 7-8). She then went to her cousin, Elizabeth, for protection. Mary soon divorced Hepburn, who later died of insanity, in a prison in the Netherlands, in 1578 ("Mary, Queen of Scots" par 12-15). Mary was accused of the Babington Plot, which involved the assassination of Elizabeth. Many say that this plot also served to trap Maria, as many people wanted to kill her. Elizabeth did not believe the accusation and refused to execute Mary. Secretly, Mary was found guilty and sentenced to be beheaded (Plaidy, Haws English Capti. par 1 Return to Scots par 1). Before she was beheaded at Fotheringhay Castle in 1587, Mary wrote a four-page letter to her brother-in-law Henry III, King of France. Overall, Mary had a very complicated and hard life (Briley par