Pyne inherited a sixteenth century Desmond castle at Lisfinny, near Lismore. In 1885 he was elected M.P. for West Waterford on the Home Rule ticket, defeating Sir Richard Keane Bart. He was a member of the Land League movement. The police identified him as a troublemaker. Pyne discovered that they were about to arrest him on a charge of  incitement in 1888. He stocked his tower with provisions and barricaded himself inside. A state of siege existed for many months. He eventually escaped and fled to England. However he was arrested three weeks later outside the House of Commons and was returned for trial to Kilmacthomas. He served a six week jail sentence. A few months later he disappeared. It was presumed that he drowned while crossing the Irish Sea by ferry.