From superstition to science, from bloodletting to synthetic plasma, this four-part series presents a history of humankind's understanding of the liquid that pulses through its veins. These programs gather an impressive array of guests and experts to examine the milestones in the study of blood, as well as look at the successes and tragedies of efforts to stockpile this vital substance. Symbol of life and death, health and disease, race and religion, blood becomes the vehicle for a fascinating journey of discovery.