From stone-age Hawaii to 16th-century Japan, from Ancient Greece to the Byzantine Empire, elite combat troops -- men trained to perfection, skilled with a devastating array of weaponry -- have been called upon to infiltrate, disrupt and destroy the enemy. "Ancient Assassins" illustrates the tactics of these highly trained killers, showcasing the fatal tactics, immense physical strength and treacherous know-how of the most feared assassins, elite units and mercenaries throughout time. Each hourlong episode brings history to life with a mixture of dramatic reconstruction and documentary filming. Plus, interviews with military commanders help draw modern-day comparisons to today's special forces.