1914. Prince Alek of Austria-Hungary goes on an unusual practice session in a Stormwalker. In Edinburgh, Sharp eagerly takes flight in a Huxley.

As Europe teeters on the edge of an all-out war, Alek struggles with his new life in hiding. Sharp gets acquainted with the Leviathan and its crew.

Alek learns why he's hunted and, despite Volger's advice, sneaks out to aid the Leviathan's crew. He saves Sharp, who doesn't buy the prince's story.

With Clanker forces hot on their tail, the wounded Leviathan needs a miracle to get off the ground. Alek makes an offer the Darwinists can't refuse.

The Leviathan encounters a deadly Clanker weapon on its journey towards Istanbul. Upon arriving in the city, Alek and his comrades make plans to escape.

Sharp and Dr. Barlow finally meet the Sultan, hoping to smooth things over with a rare gift. Meanwhile, a mysterious girl saves Alek from a German patrol.

A patrol jeopardizes the British secret operation, forcing Sharp to flee into Istanbul's streets. Alek commits himself to the revolutionary army's cause.

On the day of the coup, Alek urges Klopp to leave for his safety. Later, unexpected news forces the revolutionaries to act before the Behemoth arrives.

The Leviathan and its crew arrive in Siberia to meet Barlow's uncle. He reveals the source behind numerous mysterious phenomena around the world.

Tensions run high after Alek learns the truth about his friend. But before they can talk things over, Sharp gets into a dangerous predicament.

Determined to uncover the truth about Tunguska, Alek and Sharp confront Tesla and learn about the invention responsible for the destruction: the Goliath.

Tesla issues a deadly ultimatum as a last resort. Can Sharp and Alek, stuck on opposing sides, prevent the conflict from escalating before it's too late?