Join Harry Smith of CBS's The Early Show as he leads this 3,000-year expedition through the history of the characteristically pagan holiday of Halloween. Discover how the "trick-or-treat" custom originated during the harvest festivals in ancient Ireland when food and sweets were used to coax the dead into remaining in the spirit world. Learn how Christianity tried to co-opt the celebration by turning it into All Saints Day, but how the underlying-- and sometimes controversial-- dark elements of the holiday have survived.