Before the events of Mortal Engines, the people of Airhaven got tired of constantly running from predator cities, so they inflated gas bags and flew into the air. The town travels through the air, visiting different cities.
As Airhaven is neutral, it has both Tractionists and Anti-Tractionists. During the events of Mortal Engines, it is damaged by the Stalker Shrike and has to land on the Black Island to be repaired. When it is being repaired, the pirate town Tunbridge Wheels makes an unsuccessful attempt to eat it.
In A Darkling Plain, it has become divided between Tractionists and Anti-Tractionists. Hester and Theo save Lady Naga from a slave trader. On the way out Shrike stabs a guard through the foot from below and helps them escape. Nimrod Pennyroyal falls onto the safety net along with a rival news journalist.
The net breaks and they both fall. Nimrod lands on an airship and is rescued by Shrike, while the journalist plunges to his death.