“Bloodline”is episode eight of season one of Helix.
At the end of the previous episode, “Survivor Zero”, Julia had survived the virus and the infected had gotten loose in the occupied part of the base.
Patient Zero is basically the first case discovered in a disease. In this case, Survivor Zero is the first person to survive it, which was Julia. Her eyes had gone silver in colour (and Sutton’s were the same) and very photo-sensitive.
Oddly, Dr. Hatake seemed rather upset by this, which is the first time he’s really shown emotion. And in this episode some of the reason why is discovered. And something rather surprising about Hatake.