The Celts of 43AD Britannia are a divided and warring group of tribes. But all tribal disputes are sidetracked with the arrival of General Aulus Plautius leading his army of Roman invaders. The invasion is only foreseen by rogue Druid Divis, where on his secret mission to overthrow the Romans, he finds an unlikely ally in a young Celt girl, Cait.

King Pellenor is convinced his people can destroy the Romans using force, but Kerra seeks an alternative approach. Cait struggles to connect with Divis, and soon finds she is left to fend for herself. An attempted mutiny goes wrong. General Aulus finds an ally in the Cantii’s longstanding enemy and then seeks answers from an unexpected source.

General Aulus returns from his visit to the Underworld. Pellenor is furious to learn of Kerra’s secret visit to the Romans. Divis persuades two Romans to get him into the enemy camp. Armed with the knowledge of her father’s survival, Cait reunites with Divis to provoke a change in plans.

Veran leads his troupe of Druids to Crugdunon Fortress to deliver judgment to Kerra. Events take an unexpected turn and lead to a new order for the Regni. Cait makes a confession to her father. Aulus serves his own unique sense of punishment to the Roman mutineers.

When Kerra is given a deadline to make a decision, Lindon offers her an alternative path. Phelan struggles to come to terms with the recent events, while Amena spirals down a self-destructive path. Aulus visits Queen Antedia of the Regni. Divis seeks answers in the Underworld.

Divis receives a deadly mission. Kerra adjusts to her new role as vendettas are plotted against her. Cait and her father find peace at Crugdunon but it is short lived. Aulus agrees to talks with Kerra but is sidetracked by his own personal mission.

Camped out in a deserted village, Phelan is not convinced by Ania’s confidence in their prophecy. Cait and Sawyer find solace but it is cut short when Divis’ demon Pwykka tracks them down. Roman deserters, Brutus and Philo, contemplate the gods.

The Cantii are still under siege from the Regni. Antedia uses a spy to her advantage. Aulus, sidetracked by his personal mission, tasks three sets of assassins to track down Cait. Lucius’ mistrust of Aulus grows and his actions lead to fatal consequences. Cait struggles to meet Divis’ expectations and his inability to protect her leads to a devastating end.

Divis tries to track down the abducted Cait. The siege of the Cantii reaches a bitter and violent end. Phelan and Ania seek answers from Druid Veran. Veran considers the hope that is left for them all in the form of Cait.