Battlestar Galactica - Season 1 - Eps 7: Six Degrees of Separation
When Baltar and the Number Six who lives in his head have a falling out, she abandons him, only to surface a short while later aboard the Galactica. But now she's called Shelley Godfrey, everyone can see her, and she's telling them that she has evidence, passed on by the late Dr. Amarak, that will prove Baltar sold out the human race to the Cylons.
About Battlestar Galactica

Title: Battlestar Galactica
First Air Date: 2004-10-18
Last Air Date: 2009-03-20
Status: Ended
Rating: 8.2/10 (from 1582 votes)
Language: EN
Seasons: 5
Total Episodes: 73
Network: Syfy
Genres: Sci-Fi & Fantasy, Action & Adventure, Drama
Production Companies: David Eick Productions, R&D TV, Universal Television, Universal Media Studios, UCP
Synopsis
When an old enemy, the Cylons, resurface and obliterate the 12 colonies, the crew of the aged Galactica protect a small civilian fleet - the last of humanity - as they journey toward the fabled 13th colony, Earth.
Cast

Edward James Olmos
William Adama

Mary McDonnell
Laura Roslin

Jamie Bamber
Lee 'Apollo' Adama

Katee Sackhoff
Kara 'Starbuck' Thrace

James Callis
Gaius Baltar

Tricia Helfer
Number Six

Tahmoh Penikett
Karl 'Helo' Agathon

Grace Park
Sharon 'Boomer' Valerii

Michael Hogan
Saul Tigh

Aaron Douglas
Galen Tyrol