Capt. Matthew Gideon assembles the crew that will be with him on the experimental starship Excalibur. Their mission: explore the reaches of space to find a cure for the deadly Drakh virus that will overrun Earth in five years.

Gideon mediates between Earth miners and the residents of a planet containing a virus-fighting mineral--and a fire-breathing dragon.

Galen persuades Gideon to seek a mystical crossroads. An investigator probes Matheson's mind.

A mysterious sphere prompts Gideon and the others to relive traumatic moments from their past.

Gideon must deport a colony of renegade humans. Dureena finds a lost tribe of her people.

Gideon and Lochley must prevent a doomsday cult from killing everyone at a virus conference on Mars.

The Excalibur goes to Babylon 5 so that Gideon can meet with an ambassador for permission to go to a planet that might have technology that can help Earth. But the ambassador refuses and Gideon is not going to accept it. And Ellerson runs into his ex-wife, who is in trouble with a loan shark. When he pays him off, he feels she owes him more. And goes to great lengths to collect.

Gideon must outwit an alien consciousness that takes over the Excalibur's crew.

Gideon and crew find themselves trapped by an alien civilization using sinister methods to seek a cure for the same Drakh virus that attacked Earth.

Galen warns Gideon not to explore a planet where the inhabitants were suddenly eradicated.

Gideon conducts an illegal raid to free a fugitive with information that could save Earth.

Two persecuted alien investigators (based on FBI agents Mulder and Scully from X-Files) believe that Earth is covertly invading them.

In an attempt to understand the nature of the Drakh virus better, the Excalibur is sent back to Earth's orbit for a top-secret special pick up. Familiar face returns. Final, open-ended, episode.