Leaving behind his homeland, Zinkenstill, Gran continues his journey with the other skyfaring crew members, hoping to reach the Island of the Astrals.

Gran and the others are on the run from the Erste Empire, when out of the blue, the Empire proposes peace talks, and the crew heads to the Albion Citadel for the negotiations.

Gran and his crew are acquitted, thanks to the Erste Empire's pardon. But the morning after the banquet, they wake up to find Katalina gone, having left behind only a letter.

Due to a past incident, Katalina feels indebted to Vira and wants to provide her support after the many years of pressure and loneliness Vira has endured as Lord Commander.

After leaving Albion, the Grandcypher lands on an island shrouded in thick mist, notorious for being inescapable.

Lyria, Io, and Orchis have been swallowed by Celeste. Left behind, Gran and the others search for a way to save them, along with a ghost girl, Ferry, whom they met in the village.

Celeste is being manipulated by someone. Someone who has forced the primal to attack the village and devour its undead residents. Gran takes the chance to leap into Celeste to rescue Lyria, Io, and Orchis.

Gran and the others head to Golonzo Island, known as the mecca of shipbuilding, in order to repair the damaged Grandcypher.

Under the command of Pommern, the imperial army takes Gran and Lyria away. Meanwhile, Noa is held captive in a research lab as he suffers from the effects of dark essence.

Gran and Lyria escape from the empire's garrison and are reunited with Rackam and the others. Noa tries to resurrect the Grandcypher that had been damaged by the empire's strike, but finds himself too weak to provide sufficient power. He suggests they ask Mithra, the primal beast of promises on Golonzo, to help them.

The Black Knight, trapped by her own past, is set on attaining Lyria's power, but Gran vows adamantly to protect Lyria. Their unwavering beliefs clash, neither willing to bend.