From the introduction:
The War of the Roses, a power struggle between the Houses of Lancaster (Red Rose) and York (White Rose) to decide a royal successor, was nearing an end. With the Yorkists well in the lead, the reign of Richard 3 was but a step away. And in France, Yugi (Henry Tudor) – the last Lancastrian heir – was being forced to live a life of exile. The Lancastrian forces were rendered powerless by ancient cards of sorcery wielded by “Seto” and his 7 followers who, known as the “Rose Crusaders”, served under the flag of Lord Crawford, a powerful Yorkist nobleman. Lacking a duelist to champion their cause, defeat was imminent for the Lancastrians. In England, duel card games were still at the fledgling stage. Thus, the Lancastrians had to look elsewhere for a duel master capable of facing the Rosenkreuz in battle. With this in mind, Margaret Mai Beaufort of Lancaster secretly requested a High Druid to summon a duelist from another age.