Following the arrest and detention of the famous activist artist in China, Ai Weiwei remotely transforms the former island penitentiary of Alcatraz into a remarkable expression of socially-engaged art focused on the plight of the unjustly incarcerated. Human rights become profoundly personal when this monumental exhibition inspires thousands of visitors to write to prisoners of conscience worldwide. What no one expected was that the messages would actually get through and what they would mean.