As the Avalon Expedition departs the Tantalus Cluster for an extra-galactic nebula in search of resources, the crew of the Guinevere discover a mysterious new threat.

Cass struggles with her new situation as she leads a mission to recover a crucial Gate component from a wrecked ship.

Cass and Elizabeth must rely on each other to survive on a mysterious planet whose surface has been scorched to glass by the formation of a nearby pulsar.

When a desperate civilian vessel arrives at the Avalon, Lieutenant Ravi must respond to an increasingly dangerous situation in the Director's absence.

After months of surviving the dangerous nebula without military protection, the careful status quo built by the Avalon Expedition is disrupted by the unexpected arrival of Vice Admiral Redfield.

With Elizabeth and Cass trapped in the Avalon’s brig, the expedition’s crews prove increasingly discontent with the new authority of Admiral Redfield.

Following a distress call from expedition vessels lost deep in the Sanctum, Vadric accompanies the Guin crew on a daring rescue mission.

Uncovering a force of Frontier Union vessels hiding in the nebula, the Avalon Expedition offers assistance, but the Unioners have an agenda of their own.

In a daring raid on a strange and alien installation, Admiral Redfield and the crew of the Guinevere attempt to retake their stolen Gatehauler from the clutches of the Advari.

The crew of the Avalon prepares for the worst as a fleet of Advari Lightships slowly draws near.

The Avalon Expedition makes its last stand as the now-unified forces of the three nations of Tantalus confront the Advari in a climactic battle.