Sarah Teller is a character first encountered in season 3, spisode 1 "No Mercy".
Pre Apocalypse Edit
Before the outbreak started Sarah was working with her husband Dr. Harold Teller studying mycologi at Mercy Labs. They had a son, Andrew.
Post Apocalypse Edit
Sarah is working on a cure for the ZN1 virus when the lab is overrun by zombies. There is an explosion that causes the fungi to spread and infects the people trapped in the lab. She is infected and kept in the sealed lab by her husband.
When Murphy wanders in to the lab four years later she can finally comunicate and through him she tells Harold that she wants to die.
As the compund is attacked by The Man she sacrifices herself in order to save her husband.
Harold tell Sarah he loves her, gives her a last kiss and the puts a gun to her head.