After surviving the Battle of Cape Ecnomus in 256 BC, Tontorix and Diaecus relocate to Phoenicia where they assimilate themselves into the culture by learning the language, adopting new names, and joining the lucrative purple dye manufacturing business. When rule over the Phoenicians passes from the Ptolemaic Empire to the Seleucid Empire, the two companions are compelled to avoid paying new taxes by traveling to Taxila in the east and establishing trade with the Mauryan Empire.

Eventually, Diaecus returns to Phoenician shores to find that the city they called home has succumbed to the power of local gangs. Intent on standing up for innocent citizens and what he believes to be right, he is motivated to learn new skills to challenge the gangs on their own turf. Meanwhile, Tontorix remains in Taxila as the Mauryan Empire comes to an end and the turbulent Greco-Bactrian Kingdom sweeps in to establish the Indo-Greek Kingdom.

Both situations come to a climax as the two Celts struggle with their different perceptions of what it means to be a good leader and a positive influence on the people and places they care about.