After the Defenestration of Prague in 1618, the young elector Frederick V of the Palatinate and his wife Elisabeth Stuart are crowned King and Queen of Bohemia - an affront to the Habsburg emperor. More and more European powers are drawn into the conflict, and the inexperienced royal couple quickly lose control of events.

The Catholic armies are attacked by an immense empire from the north: Denmark. At the same time, the Catholic Spanish Netherlands are fighting the separatist Dutch Protestants. Peter Paul Rubens, now a spy for Isabella of Spain, travels to Paris to meet with Father Joseph, Cardinal Richelieu's right hand. France is on the brink of war with England. In La Rochelle, events are coming to a head.

Ferdinand II, the Holy Roman Emperor intends to re-Catholicise numerous possessions - by consent or by force. Peter Hagendorf, fighting in the Imperial army, is injured during the Sack of Magdeburg. Anna von Haugwitz escapes the massacre of Protestant Calbe; her entire family is wiped out. Father Joseph takes part in the Diet of Regensburg where the emperor's rise to power is put to an end.

Sweden's intervention fundamentally changes the situation. King Gustavus Adolphus is more than a match for the Imperial forces led by General Wallenstein. City by city, territory is snatched from the emperor. Henrik Holck is now fighting on Wallenstein's side in Lützen. In a time of famine and pestilence, tavern owner Barbara Xeller profits from the arrival of the Lutheran Swedish troops in Biberach.

The Holy Roman Empire lies in ruins. Thousands of Scottish, Italian, English, and Swiss mercenaries come to pick over the spoils. Father Joseph and Cardinal Richelieu has recruited 40,000 new soldiers for France, seemingly out of nowhere. Near Magdeburg, Anna von Haugwitz meets Swedish commander Carl Gustaf Wrangel; from then on, she follows him from camp to camp.