Complex sentence: It ties the Molly Maguire background to another event of that period: the death of James Carey, the informer on the Irish National Invincibles who committed the Phoenix Park murders of Lord Frederick Cavendish and Thomas Burke.
Split into simpler sentences: It ties the Molly Maguire background to another sensation of that period. This was the death of James Carey, the informer on the Irish National Invincibles who committed the Phoenix Park murders of Lord Frederick Cavendish and Thomas Burke.