Phoebe (Alyssa Milano) pays a visit to Alcatraz, the former federal prison-turned-national museum. Here she is confronted by the ghost of a serial killer, executed at the prison decades earlier. The malevolent ghost intends to embark upon another murder spree -- using the body of a live guard as his "vehicle." Can Phoebe handle this crisis alone, or will she have to call upon her sisters, Piper (Holly Marie Combs) and Prue (Shannen Doherty), who at present have a few problems of their own? Be prepared for a major shock before this story plays itself out.