Episode 3x3, Further Instructions
Locke and Charlie find Eko in a cave after he was dragged off by a polar bear. He is out of it as the two take him back to camp, but comes to long enough to tell Locke that he can save Jack, Kate, and Sawyer and that Locke is a hunter.Episode 3x5, The Cost of Living
Eko sees his brother, Yemi, in his tent, then his tent bursts into flames. Charlie and Hurley pull him out, but then he disappears. Locke figures out that he's going to the drug plane, and follows him. Locke finds him at a stream and realizes that Eko saw something, but Eko won't tell him what. Eko had seen the smoke monster.Eko pulls a knife on Locke when Locke mentions Yemi's name. Outside the Pearl Station, while the others are inside, Eko follows his brother, but he does not confess. Eko says that he has not sinned. He did the stuff he did because he had to in order to survive.
The smoke monster grabs Eko and beats him against a tree. Eko lays on the ground and Locke finds him. He whispers to Locke, then dies.
