The Lost Horizons campaign takes place in the Astral Plane in the year 1996 DR. The players are a group of adventurers hired to explore the far reaches of the plane and investigate strange occurrences.
The campaign begins with the players arriving in the Lumina capital city of Aethergarde, where they meet with Queen Eadric and her advisors. They are given a mission to investigate a series of mysterious disappearances in a remote region of the plane known as the Silver Expanse. The players are also tasked with uncovering the source of a strange energy disturbance that has been affecting the plane's natural flow.
Throughout the campaign, the players also have the opportunity to engage in trade, diplomacy, and exploration with the various factions and races of the Astral Plane. They may also encounter other adventurers and mercenaries who are seeking their own fortunes on the plane.