"The Passage" is the tenth episode of the third season from the science fiction television series Battlestar Galactica. It aired on December 8, 2006.
Plot
The fleet's food supply has been contaminated, forcing everyone to subsist on rapidly dwindling food rations. Athena, who has been doing reconnaissance, discovers a planet where abundant algae is found that can be used as a nutritious, if unappetizing, food source. Unfortunately, the planet is located on the other side of a vast, highly radioactive star cluster that is too big to go around. The fleet must cross the cluster or risk starvation. Because of the size of the cluster, each ship must jump to a point within it before jumping again to the planet.
Admiral Adama proposes that each civilian ship be paired with a Raptor, which will serve as a guide for each ship and direct it safely towards the algae planet. Each pilot is issued a white radiation warning badge which turns solid black when the pilot has been exposed to their maximum safe level of radiation. At that point that pilot is to be pulled off the operation.
Following the strategy meeting, Kat is approached by a disheveled-looking man named Enzo who addresses her as "Sasha", the man tells her she cannot deny who she really is. Enzo continues to harass her, trying to get her to cooperate in some unnamed and apparently criminal activity. It is evident that the two know each other, despite Kat's protestations to the contrary.
Starbuck spies on one of their conversations, questions Enzo and then confronts Kat about what she heard. Kat tearfully admits she was once a "trucker" — a smuggler of drugs and of criminals, and says she stole the identity of a woman who had died just prior to the Cylon attack on the Colonies. Starbuck says one theory behind the success of the Cylon attack was that the Cylons might have infiltrated Caprica with aid from smugglers like Kat.
Deeply shaken by the insinuation she is a traitor, Kat retorts at the time the Colonials didn't know some Cylons had human appearances. If any were Cylons, she wasn't aware, and begs Starbuck not to tell Admiral Adama. Kat tells Starbuck she will tell him herself.
Inside the Cylon fleet, Gaius Baltar grows concerned about the strange behavior of a Number Three. Wondering what she could possibly be up to, he learns from Caprica Six that her behavior is causing concern among the other Cylons as well. Baltar confronts Three, learning that she keeps committing suicide and resurrecting, over and over again. Three says that during her resurrections, she sees the five humanoid Cylons that have yet to be revealed, even drawing pictures of them. Baltar, still wondering if he could be a Cylon himself, asks if he is one of the remaining five, but Three says her visions are muddled and she can give no further details.
Back at the Colonial fleet, many of Galactica's pilots help execute Apollo's plan. As the mission proceeds, the pilots become more and more fatigued and sickened by the intense radiation. Kat in particular is traumatized by the loss of two ships, the Adriatic (which was being escorted by Hot Dog) and the Carina (which was being escorted by Kat herself).
Kat is plunged into a deep state of depression from a combination of guilt about her false identity, the loss of the ships, and the physical and psychological stresses of flying through the cluster itself. In her depression, she steals a white radiation badge (out of Helo's locker) and uses it to replace her own black one. She also conceals that her hair has started to fall out due to overexposure to radiation.
Kat makes one last attempt to guide a civilian ship. This time, like the others, the civilian ship goes adrift and becomes hidden by the brilliant light of the cluster. The mid-cluster jump point rapidly becomes unstable and even more lethal, prompting Admiral Adama to order all Raptors to jump to the planet, whether or not they have located their associated civilian ship. Kat vows not to lose another ship and disobeys the order. In her persistent efforts to locate the lost ship, she is exposed to a lethal dose of radiation. She successfully guides the ship to the algae planet. When she returns to Galactica, she is greeted with a round of applause from Adama and much of the Galactica crew, Starbuck included. However, she collapses as soon as she gets out of her Raptor.