Sarah Chambers is the Excalibur's Chief Medical Officer. She was on Mars at the time of the Drakh attack and chose to join the crew rather than return to Earth and be with her family. She is especially driven to find a cure by the fact that her sister was on Earth at the time of the Drakh attack and is infected with the plague.
In 2267 Chambers became the Head of the Medical Staff on board the Excalibur. She identified that a mineral was causing the people to become contaminated. She found out that the people on Theta 49 were contaminated with the plague. Chambers then went through their trash and found out that their food was contaminated. She then went to find Dureena and finds her and her own people. Dureena makes her promise to tell no one. She then was taken hostage by one of the infected colonists and she was taken with them. They end up surrendering though. She then find out that Dureena's people only had a year before they would die from the plague.
She was then asked to give the keynote speech at a conference about the plague. When she does give her speech, Gideon interrupts it and says they made a miscalculation and that it would take a few months not five years for the virus to adapt to humans and wipe out all life on Earth .Later this was taken back and she gave the rest of her speech.
Attempted Alien Takeover of Excalibur
When she tried to save an alien they had found it started to die. One of the crew ran in and tried to save the alien. The alien grabs her and then dies. While Chambers was scanning the creature she saw that the creature had multiple brain waves. This crew member has been taken over and attempt to infect the rest of the crew and take over the IAS Excalibur
When the crew started getting killed in unknown circumstances Chambers autopsies them and find out that a nanovirus caused them to kill each other without them knowing it. Then Galen asks her to zoom in on part of the virus and they find out that a Technomage made the virus. Galen storms out and goes down to the planet where he destroys the other Technomage. When Galen gets back he needed to be treated for a shoulder wound. When Dr. Chambers asks him to take off his shirt he does and she finds machines attached to his back. Galen then helps Chambers to adapt the nanovirus to become a filter so that people could actually walk on Earth with out getting infected but only for 48 hrs.
Medical Test to Develop a Cure
Later Dr. Franklin came aboard to do an experiment on a human who was willing to be infected by the plague. They did this and they found out that the virus was only affecting major organs and not anything else, almost like it knew where it was going. Then they found out that the virus was a nanovirus. Then the ship was attacked by the Drakh and the sterilization process was accidentally started. Franklin rescued the man who had volunteered and later went back to Earth with him.
- Crusade (11 episodes)